text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "content/browser/browser_main_loop.h"
  
  #include "base/bind.h"
  #include "base/command_line.h"
  #include "base/debug/trace_event.h"
  #include "base/file_util.h"
  #include "base/logging.h"
  #include "base/message_loop/message_loop.h"
  #include "base/metrics/field_trial.h"
  #include "base/metrics/histogram.h"
  #include "base/path_service.h"
  #include "base/pending_task.h"
  #include "base/power_monitor/power_monitor.h"
  #include "base/power_monitor/power_monitor_device_source.h"
  #include "base/process/process_metrics.h"
  #include "base/run_loop.h"
  #include "base/strings/string_number_conversions.h"
  #include "base/system_monitor/system_monitor.h"
  #include "base/thread_task_runner_handle.h"
  #include "base/threading/thread_restrictions.h"
  #include "base/timer/hi_res_timer_manager.h"
  #include "content/browser/battery_status/battery_status_service.h"
  #include "content/browser/browser_thread_impl.h"
  #include "content/browser/device_sensors/device_inertial_sensor_service.h"
  #include "content/browser/download/save_file_manager.h"
  #include "content/browser/gamepad/gamepad_service.h"
  #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
  #include "content/browser/gpu/compositor_util.h"
  #include "content/browser/gpu/gpu_data_manager_impl.h"
  #include "content/browser/gpu/gpu_process_host.h"
  #include "content/browser/gpu/gpu_process_host_ui_shim.h"
  #include "content/browser/histogram_synchronizer.h"
  #include "content/browser/loader/resource_dispatcher_host_impl.h"
  #include "content/browser/media/capture/audio_mirroring_manager.h"
  #include "content/browser/media/media_internals.h"
  #include "content/browser/net/browser_online_state_observer.h"
  #include "content/browser/plugin_service_impl.h"
  #include "content/browser/renderer_host/media/media_stream_manager.h"
  #include "content/browser/speech/speech_recognition_manager_impl.h"
  #include "content/browser/startup_task_runner.h"
  #include "content/browser/time_zone_monitor.h"
  #include "content/browser/webui/content_web_ui_controller_factory.h"
  #include "content/browser/webui/url_data_manager.h"
  #include "content/public/browser/browser_main_parts.h"
  #include "content/public/browser/browser_shutdown.h"
  #include "content/public/browser/content_browser_client.h"
  #include "content/public/browser/render_process_host.h"
  #include "content/public/browser/tracing_controller.h"
  #include "content/public/common/content_switches.h"
  #include "content/public/common/main_function_params.h"
  #include "content/public/common/result_codes.h"
  #include "crypto/nss_util.h"
  #include "media/audio/audio_manager.h"
  #include "media/base/media.h"
  #include "media/base/user_input_monitor.h"
  #include "media/midi/midi_manager.h"
  #include "net/base/network_change_notifier.h"
  #include "net/socket/client_socket_factory.h"
  #include "net/ssl/ssl_config_service.h"
  #include "ui/base/clipboard/clipboard.h"
  
  #if defined(USE_AURA) || (defined(OS_MACOSX) && !defined(OS_IOS))
  #include "content/browser/compositor/image_transport_factory.h"
  #endif
  
  #if defined(USE_AURA)
  #include "content/public/browser/context_factory.h"
  #include "ui/aura/env.h"
  #endif
  
  #if !defined(OS_IOS)
  #include "content/browser/renderer_host/render_process_host_impl.h"
  #endif
  
  #if defined(OS_ANDROID)
  #include "base/android/jni_android.h"
  #include "content/browser/android/browser_startup_controller.h"
  #include "content/browser/android/surface_texture_peer_browser_impl.h"
  #include "content/browser/android/tracing_controller_android.h"
  #include "ui/gl/gl_surface.h"
  #endif
  
  #if defined(OS_MACOSX) && !defined(OS_IOS)
  #include "content/browser/bootstrap_sandbox_mac.h"
  #include "content/browser/cocoa/system_hotkey_helper_mac.h"
  #include "content/browser/theme_helper_mac.h"
  #endif
  
  #if defined(OS_WIN)
  #include <windows.h>
  #include <commctrl.h>
  #include <shellapi.h>
  
  #include "content/browser/system_message_window_win.h"
  #include "content/common/sandbox_win.h"
  #include "net/base/winsock_init.h"
  #include "ui/base/l10n/l10n_util_win.h"
  #endif
  
  #if defined(USE_GLIB)
  #include <glib-object.h>
  #endif
  
  #if defined(OS_LINUX) && defined(USE_UDEV)
  #include "content/browser/device_monitor_udev.h"
  #elif defined(OS_MACOSX) && !defined(OS_IOS)
  #include "content/browser/device_monitor_mac.h"
  #endif
  
  #if defined(OS_POSIX) && !defined(OS_MACOSX)
  #include "content/browser/renderer_host/render_sandbox_host_linux.h"
  #include "content/browser/zygote_host/zygote_host_impl_linux.h"
  #include "sandbox/linux/suid/client/setuid_sandbox_client.h"
  #endif
  
  #if defined(TCMALLOC_TRACE_MEMORY_SUPPORTED)
  #include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h"
  #endif
  
  #if defined(USE_X11)
  #include "ui/gfx/x/x11_connection.h"
  #include "ui/gfx/x/x11_types.h"
  #endif
  
  // One of the linux specific headers defines this as a macro.
  #ifdef DestroyAll
  #undef DestroyAll
  #endif
  
  namespace content {
  namespace {
  
  #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
  void SetupSandbox(const base::CommandLine& parsed_command_line) {
    TRACE_EVENT0("startup", "SetupSandbox");
    base::FilePath sandbox_binary;
  
    scoped_ptr<sandbox::SetuidSandboxClient> setuid_sandbox_client(
        sandbox::SetuidSandboxClient::Create());
  
    const bool want_setuid_sandbox =
        !parsed_command_line.HasSwitch(switches::kNoSandbox) &&
        !parsed_command_line.HasSwitch(switches::kDisableSetuidSandbox) &&
        !setuid_sandbox_client->IsDisabledViaEnvironment();
  
    static const char no_suid_error[] =
        "Running without the SUID sandbox! See "
        "https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment "
        "for more information on developing with the sandbox on.";
    if (want_setuid_sandbox) {
      sandbox_binary = setuid_sandbox_client->GetSandboxBinaryPath();
      if (sandbox_binary.empty()) {
        // This needs to be fatal. Talk to security@chromium.org if you feel
        // otherwise.
        LOG(FATAL) << no_suid_error;
      }
    } else {
      LOG(ERROR) << no_suid_error;
    }
  
    // Tickle the sandbox host and zygote host so they fork now.
    RenderSandboxHostLinux::GetInstance()->Init();
    ZygoteHostImpl::GetInstance()->Init(sandbox_binary.value());
  }
  #endif
  
  #if defined(USE_GLIB)
  static void GLibLogHandler(const gchar* log_domain,
                             GLogLevelFlags log_level,
                             const gchar* message,
                             gpointer userdata) {
    if (!log_domain)
      log_domain = "<unknown>";
    if (!message)
      message = "<no message>";
  
    if (strstr(message, "Unable to retrieve the file info for")) {
      LOG(ERROR) << "GTK File code error: " << message;
    } else if (strstr(message, "Could not find the icon") &&
               strstr(log_domain, "Gtk")) {
      LOG(ERROR) << "GTK icon error: " << message;
    } else if (strstr(message, "Theme file for default has no") ||
               strstr(message, "Theme directory") ||
               strstr(message, "theme pixmap") ||
               strstr(message, "locate theme engine")) {
      LOG(ERROR) << "GTK theme error: " << message;
    } else if (strstr(message, "Unable to create Ubuntu Menu Proxy") &&
               strstr(log_domain, "<unknown>")) {
      LOG(ERROR) << "GTK menu proxy create failed";
    } else if (strstr(message, "Out of memory") &&
               strstr(log_domain, "<unknown>")) {
      LOG(ERROR) << "DBus call timeout or out of memory: "
                 << "http://crosbug.com/15496";
    } else if (strstr(message, "Could not connect: Connection refused") &&
               strstr(log_domain, "<unknown>")) {
      LOG(ERROR) << "DConf settings backend could not connect to session bus: "
                 << "http://crbug.com/179797";
    } else if (strstr(message, "Attempting to store changes into") ||
               strstr(message, "Attempting to set the permissions of")) {
      LOG(ERROR) << message << " (http://bugs.chromium.org/161366)";
    } else if (strstr(message, "drawable is not a native X11 window")) {
      LOG(ERROR) << message << " (http://bugs.chromium.org/329991)";
    } else {
      LOG(DFATAL) << log_domain << ": " << message;
    }
  }
  
  static void SetUpGLibLogHandler() {
    // Register GLib-handled assertions to go through our logging system.
    const char* kLogDomains[] = { NULL, "Gtk", "Gdk", "GLib", "GLib-GObject" };
    for (size_t i = 0; i < arraysize(kLogDomains); i++) {
      g_log_set_handler(kLogDomains[i],
                        static_cast<GLogLevelFlags>(G_LOG_FLAG_RECURSION |
                                                    G_LOG_FLAG_FATAL |
                                                    G_LOG_LEVEL_ERROR |
                                                    G_LOG_LEVEL_CRITICAL |
                                                    G_LOG_LEVEL_WARNING),
                        GLibLogHandler,
                        NULL);
    }
  }
  #endif
  
  void OnStoppedStartupTracing(const base::FilePath& trace_file) {
    VLOG(0) << "Completed startup tracing to " << trace_file.value();
  }
  
  #if defined(USE_AURA)
  bool ShouldInitializeBrowserGpuChannelAndTransportSurface() {
    return true;
  }
  #elif defined(OS_MACOSX) && !defined(OS_IOS)
  bool ShouldInitializeBrowserGpuChannelAndTransportSurface() {
    return IsDelegatedRendererEnabled();
  }
  #endif
  
  // Disable optimizations for this block of functions so the compiler doesn't
  // merge them all together. This makes it possible to tell what thread was
  // unresponsive by inspecting the callstack.
  MSVC_DISABLE_OPTIMIZE()
  MSVC_PUSH_DISABLE_WARNING(4748)
  
  NOINLINE void ResetThread_DB(scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  NOINLINE void ResetThread_FILE(scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  NOINLINE void ResetThread_FILE_USER_BLOCKING(
      scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  NOINLINE void ResetThread_PROCESS_LAUNCHER(
      scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  NOINLINE void ResetThread_CACHE(scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  NOINLINE void ResetThread_IO(scoped_ptr<BrowserProcessSubThread> thread) {
    thread.reset();
  }
  
  #if !defined(OS_IOS)
  NOINLINE void ResetThread_IndexedDb(scoped_ptr<base::Thread> thread) {
    thread.reset();
  }
  #endif
  
  MSVC_POP_WARNING()
  MSVC_ENABLE_OPTIMIZE();
  
  }  // namespace
  
  // The currently-running BrowserMainLoop.  There can be one or zero.
  BrowserMainLoop* g_current_browser_main_loop = NULL;
  
  // This is just to be able to keep ShutdownThreadsAndCleanUp out of
  // the public interface of BrowserMainLoop.
  class BrowserShutdownImpl {
   public:
    static void ImmediateShutdownAndExitProcess() {
      DCHECK(g_current_browser_main_loop);
      g_current_browser_main_loop->ShutdownThreadsAndCleanUp();
  
  #if defined(OS_WIN)
      // At this point the message loop is still running yet we've shut everything
      // down. If any messages are processed we'll likely crash. Exit now.
      ExitProcess(RESULT_CODE_NORMAL_EXIT);
  #elif defined(OS_POSIX) && !defined(OS_MACOSX)
      _exit(RESULT_CODE_NORMAL_EXIT);
  #else
      NOTIMPLEMENTED();
  #endif
    }
  };
  
  void ImmediateShutdownAndExitProcess() {
    BrowserShutdownImpl::ImmediateShutdownAndExitProcess();
  }
  
  // For measuring memory usage after each task. Behind a command line flag.
  class BrowserMainLoop::MemoryObserver : public base::MessageLoop::TaskObserver {
   public:
    MemoryObserver() {}
    virtual ~MemoryObserver() {}
  
    virtual void WillProcessTask(const base::PendingTask& pending_task) OVERRIDE {
    }
  
    virtual void DidProcessTask(const base::PendingTask& pending_task) OVERRIDE {
  #if !defined(OS_IOS)  // No ProcessMetrics on IOS.
      scoped_ptr<base::ProcessMetrics> process_metrics(
          base::ProcessMetrics::CreateProcessMetrics(
  #if defined(OS_MACOSX)
              base::GetCurrentProcessHandle(), NULL));
  #else
              base::GetCurrentProcessHandle()));
  #endif
      size_t private_bytes;
      process_metrics->GetMemoryBytes(&private_bytes, NULL);
      HISTOGRAM_MEMORY_KB("Memory.BrowserUsed", private_bytes >> 10);
  #endif
    }
   private:
    DISALLOW_COPY_AND_ASSIGN(MemoryObserver);
  };
  
  
  // BrowserMainLoop construction / destruction =============================
  
  BrowserMainLoop* BrowserMainLoop::GetInstance() {
    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
    return g_current_browser_main_loop;
  }
  
  BrowserMainLoop::BrowserMainLoop(const MainFunctionParams& parameters)
      : parameters_(parameters),
        parsed_command_line_(parameters.command_line),
        result_code_(RESULT_CODE_NORMAL_EXIT),
        created_threads_(false),
        // ContentMainRunner should have enabled tracing of the browser process
        // when kTraceStartup is in the command line.
        is_tracing_startup_(
            parameters.command_line.HasSwitch(switches::kTraceStartup)) {
    DCHECK(!g_current_browser_main_loop);
    g_current_browser_main_loop = this;
  }
  
  BrowserMainLoop::~BrowserMainLoop() {
    DCHECK_EQ(this, g_current_browser_main_loop);
  #if !defined(OS_IOS)
    ui::Clipboard::DestroyClipboardForCurrentThread();
  #endif  // !defined(OS_IOS)
    g_current_browser_main_loop = NULL;
  }
  
  void BrowserMainLoop::Init() {
    TRACE_EVENT0("startup", "BrowserMainLoop::Init");
    parts_.reset(
        GetContentClient()->browser()->CreateBrowserMainParts(parameters_));
  }
  
  // BrowserMainLoop stages ==================================================
  
  void BrowserMainLoop::EarlyInitialization() {
    TRACE_EVENT0("startup", "BrowserMainLoop::EarlyInitialization");
  
  #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
    // No thread should be created before this call, as SetupSandbox()
    // will end-up using fork().
    SetupSandbox(parsed_command_line_);
  #endif
  
  #if defined(USE_X11)
    if (parsed_command_line_.HasSwitch(switches::kSingleProcess) ||
        parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
      if (!gfx::InitializeThreadedX11()) {
        LOG(ERROR) << "Failed to put Xlib into threaded mode.";
      }
    }
  #endif
  
    // GLib's spawning of new processes is buggy, so it's important that at this
    // point GLib does not need to start DBUS. Chrome should always start with
    // DBUS_SESSION_BUS_ADDRESS properly set. See crbug.com/309093.
  #if defined(USE_GLIB)
    // g_type_init will be deprecated in 2.36. 2.35 is the development
    // version for 2.36, hence do not call g_type_init starting 2.35.
    // http://developer.gnome.org/gobject/unstable/gobject-Type-Information.html#g-type-init
  #if !GLIB_CHECK_VERSION(2, 35, 0)
    // GLib type system initialization. Needed at least for gconf,
    // used in net/proxy/proxy_config_service_linux.cc. Most likely
    // this is superfluous as gtk_init() ought to do this. It's
    // definitely harmless, so retained as a reminder of this
    // requirement for gconf.
    g_type_init();
  #endif
  
    SetUpGLibLogHandler();
  #endif
  
    if (parts_)
      parts_->PreEarlyInitialization();
  
  #if defined(OS_MACOSX)
    // We use quite a few file descriptors for our IPC, and the default limit on
    // the Mac is low (256), so bump it up.
    base::SetFdLimit(1024);
  #endif
  
  #if defined(OS_WIN)
    net::EnsureWinsockInit();
  #endif
  
  #if !defined(USE_OPENSSL)
    // We want to be sure to init NSPR on the main thread.
    crypto::EnsureNSPRInit();
  #endif  // !defined(USE_OPENSSL)
  
  #if !defined(OS_IOS)
    if (parsed_command_line_.HasSwitch(switches::kRendererProcessLimit)) {
      std::string limit_string = parsed_command_line_.GetSwitchValueASCII(
          switches::kRendererProcessLimit);
      size_t process_limit;
      if (base::StringToSizeT(limit_string, &process_limit)) {
        RenderProcessHost::SetMaxRendererProcessCount(process_limit);
      }
    }
  #endif  // !defined(OS_IOS)
  
    if (parts_)
      parts_->PostEarlyInitialization();
  }
  
  void BrowserMainLoop::MainMessageLoopStart() {
    TRACE_EVENT0("startup", "BrowserMainLoop::MainMessageLoopStart");
    if (parts_) {
      TRACE_EVENT0("startup",
          "BrowserMainLoop::MainMessageLoopStart:PreMainMessageLoopStart");
      parts_->PreMainMessageLoopStart();
    }
  
  #if defined(OS_WIN)
    // If we're running tests (ui_task is non-null), then the ResourceBundle
    // has already been initialized.
    if (!parameters_.ui_task) {
      // Override the configured locale with the user's preferred UI language.
      l10n_util::OverrideLocaleWithUILanguageList();
    }
  #endif
  
    // Create a MessageLoop if one does not already exist for the current thread.
    if (!base::MessageLoop::current())
      main_message_loop_.reset(new base::MessageLoopForUI);
  
    InitializeMainThread();
  
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:SystemMonitor");
      system_monitor_.reset(new base::SystemMonitor);
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:PowerMonitor");
      scoped_ptr<base::PowerMonitorSource> power_monitor_source(
        new base::PowerMonitorDeviceSource());
      power_monitor_.reset(new base::PowerMonitor(power_monitor_source.Pass()));
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:HighResTimerManager");
      hi_res_timer_manager_.reset(new base::HighResolutionTimerManager);
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:NetworkChangeNotifier");
      network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
    }
  
  #if !defined(OS_IOS)
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MediaFeatures");
      media::InitializeCPUSpecificMediaFeatures();
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:AudioMan");
      audio_manager_.reset(media::AudioManager::Create(
          MediaInternals::GetInstance()));
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MidiManager");
      midi_manager_.reset(media::MidiManager::Create());
    }
    {
      TRACE_EVENT0("startup",
                   "BrowserMainLoop::Subsystem:ContentWebUIController");
      WebUIControllerFactory::RegisterFactory(
          ContentWebUIControllerFactory::GetInstance());
    }
  
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:AudioMirroringManager");
      audio_mirroring_manager_.reset(new AudioMirroringManager());
    }
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:OnlineStateObserver");
      online_state_observer_.reset(new BrowserOnlineStateObserver);
    }
  
    {
      system_stats_monitor_.reset(new base::debug::TraceEventSystemStatsMonitor(
          base::ThreadTaskRunnerHandle::Get()));
    }
  #endif  // !defined(OS_IOS)
  
  #if defined(OS_WIN)
    system_message_window_.reset(new SystemMessageWindowWin);
  #endif
  
    if (parts_)
      parts_->PostMainMessageLoopStart();
  
  #if !defined(OS_IOS)
    // Start tracing to a file if needed. Only do this after starting the main
    // message loop to avoid calling MessagePumpForUI::ScheduleWork() before
    // MessagePumpForUI::Start() as it will crash the browser.
    if (is_tracing_startup_) {
      TRACE_EVENT0("startup", "BrowserMainLoop::InitStartupTracing");
      InitStartupTracing(parsed_command_line_);
    }
  #endif  // !defined(OS_IOS)
  
  #if defined(OS_ANDROID)
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:SurfaceTexturePeer");
      SurfaceTexturePeer::InitInstance(new SurfaceTexturePeerBrowserImpl());
    }
  #endif
  
    if (parsed_command_line_.HasSwitch(switches::kMemoryMetrics)) {
      TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MemoryObserver");
      memory_observer_.reset(new MemoryObserver());
      base::MessageLoop::current()->AddTaskObserver(memory_observer_.get());
    }
  
  #if defined(TCMALLOC_TRACE_MEMORY_SUPPORTED)
    trace_memory_controller_.reset(new base::debug::TraceMemoryController(
        base::MessageLoop::current()->message_loop_proxy(),
        ::HeapProfilerWithPseudoStackStart,
        ::HeapProfilerStop,
        ::GetHeapProfile));
  #endif
  }
  
  int BrowserMainLoop::PreCreateThreads() {
    if (parts_) {
      TRACE_EVENT0("startup",
          "BrowserMainLoop::CreateThreads:PreCreateThreads");
      result_code_ = parts_->PreCreateThreads();
    }
  
  #if defined(ENABLE_PLUGINS)
    // Prior to any processing happening on the io thread, we create the
    // plugin service as it is predominantly used from the io thread,
    // but must be created on the main thread. The service ctor is
    // inexpensive and does not invoke the io_thread() accessor.
    {
      TRACE_EVENT0("startup", "BrowserMainLoop::CreateThreads:PluginService");
      PluginService::GetInstance()->Init();
    }
  #endif
  
  #if !defined(OS_IOS) && (!defined(GOOGLE_CHROME_BUILD) || defined(OS_ANDROID))
    // Single-process is an unsupported and not fully tested mode, so
    // don't enable it for official Chrome builds (except on Android).
    if (parsed_command_line_.HasSwitch(switches::kSingleProcess))
      RenderProcessHost::SetRunRendererInProcess(true);
  #endif
    return result_code_;
  }
  
  void BrowserMainLoop::CreateStartupTasks() {
    TRACE_EVENT0("startup", "BrowserMainLoop::CreateStartupTasks");
  
    // First time through, we really want to create all the tasks
    if (!startup_task_runner_.get()) {
  #if defined(OS_ANDROID)
      startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
          base::Bind(&BrowserStartupComplete),
          base::MessageLoop::current()->message_loop_proxy()));
  #else
      startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
          base::Callback<void(int)>(),
          base::MessageLoop::current()->message_loop_proxy()));
  #endif
      StartupTask pre_create_threads =
          base::Bind(&BrowserMainLoop::PreCreateThreads, base::Unretained(this));
      startup_task_runner_->AddTask(pre_create_threads);
  
      StartupTask create_threads =
          base::Bind(&BrowserMainLoop::CreateThreads, base::Unretained(this));
      startup_task_runner_->AddTask(create_threads);
  
      StartupTask browser_thread_started = base::Bind(
          &BrowserMainLoop::BrowserThreadsStarted, base::Unretained(this));
      startup_task_runner_->AddTask(browser_thread_started);
  
      StartupTask pre_main_message_loop_run = base::Bind(
          &BrowserMainLoop::PreMainMessageLoopRun, base::Unretained(this));
      startup_task_runner_->AddTask(pre_main_message_loop_run);
  
  #if defined(OS_ANDROID)
      if (BrowserMayStartAsynchronously()) {
        startup_task_runner_->StartRunningTasksAsync();
      }
  #endif
    }
  #if defined(OS_ANDROID)
    if (!BrowserMayStartAsynchronously()) {
      // A second request for asynchronous startup can be ignored, so
      // StartupRunningTasksAsync is only called first time through. If, however,
      // this is a request for synchronous startup then it must override any
      // previous call for async startup, so we call RunAllTasksNow()
      // unconditionally.
      startup_task_runner_->RunAllTasksNow();
    }
  #else
    startup_task_runner_->RunAllTasksNow();
  #endif
  }
  
  int BrowserMainLoop::CreateThreads() {
    TRACE_EVENT0("startup", "BrowserMainLoop::CreateThreads");
  
    base::Thread::Options io_message_loop_options;
    io_message_loop_options.message_loop_type = base::MessageLoop::TYPE_IO;
    base::Thread::Options ui_message_loop_options;
    ui_message_loop_options.message_loop_type = base::MessageLoop::TYPE_UI;
  
    // Start threads in the order they occur in the BrowserThread::ID
    // enumeration, except for BrowserThread::UI which is the main
    // thread.
    //
    // Must be size_t so we can increment it.
    for (size_t thread_id = BrowserThread::UI + 1;
         thread_id < BrowserThread::ID_COUNT;
         ++thread_id) {
      scoped_ptr<BrowserProcessSubThread>* thread_to_start = NULL;
      base::Thread::Options options;
  
      switch (thread_id) {
        case BrowserThread::DB:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::DB");
          thread_to_start = &db_thread_;
          options.timer_slack = base::TIMER_SLACK_MAXIMUM;
          break;
        case BrowserThread::FILE_USER_BLOCKING:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::FILE_USER_BLOCKING");
          thread_to_start = &file_user_blocking_thread_;
          break;
        case BrowserThread::FILE:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::FILE");
          thread_to_start = &file_thread_;
  #if defined(OS_WIN)
          // On Windows, the FILE thread needs to be have a UI message loop
          // which pumps messages in such a way that Google Update can
          // communicate back to us.
          options = ui_message_loop_options;
  #else
          options = io_message_loop_options;
  #endif
          options.timer_slack = base::TIMER_SLACK_MAXIMUM;
          break;
        case BrowserThread::PROCESS_LAUNCHER:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::PROCESS_LAUNCHER");
          thread_to_start = &process_launcher_thread_;
          options.timer_slack = base::TIMER_SLACK_MAXIMUM;
          break;
        case BrowserThread::CACHE:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::CACHE");
          thread_to_start = &cache_thread_;
          options = io_message_loop_options;
          options.timer_slack = base::TIMER_SLACK_MAXIMUM;
          break;
        case BrowserThread::IO:
          TRACE_EVENT_BEGIN1("startup",
              "BrowserMainLoop::CreateThreads:start",
              "Thread", "BrowserThread::IO");
          thread_to_start = &io_thread_;
          options = io_message_loop_options;
          break;
        case BrowserThread::UI:
        case BrowserThread::ID_COUNT:
        default:
          NOTREACHED();
          break;
      }
  
      BrowserThread::ID id = static_cast<BrowserThread::ID>(thread_id);
  
      if (thread_to_start) {
        (*thread_to_start).reset(new BrowserProcessSubThread(id));
        (*thread_to_start)->StartWithOptions(options);
      } else {
        NOTREACHED();
      }
  
      TRACE_EVENT_END0("startup", "BrowserMainLoop::CreateThreads:start");
    }
    created_threads_ = true;
    return result_code_;
  }
  
  int BrowserMainLoop::PreMainMessageLoopRun() {
    if (parts_) {
      TRACE_EVENT0("startup",
          "BrowserMainLoop::CreateThreads:PreMainMessageLoopRun");
      parts_->PreMainMessageLoopRun();
    }
  
    // If the UI thread blocks, the whole UI is unresponsive.
    // Do not allow disk IO from the UI thread.
    base::ThreadRestrictions::SetIOAllowed(false);
    base::ThreadRestrictions::DisallowWaiting();
    return result_code_;
  }
  
  void BrowserMainLoop::RunMainMessageLoopParts() {
    TRACE_EVENT_BEGIN_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
  
    bool ran_main_loop = false;
    if (parts_)
      ran_main_loop = parts_->MainMessageLoopRun(&result_code_);
  
    if (!ran_main_loop)
      MainMessageLoopRun();
  
    TRACE_EVENT_END_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
  }
  
  void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
    if (!created_threads_) {
      // Called early, nothing to do
      return;
    }
    TRACE_EVENT0("shutdown", "BrowserMainLoop::ShutdownThreadsAndCleanUp");
  
    // Teardown may start in PostMainMessageLoopRun, and during teardown we
    // need to be able to perform IO.
    base::ThreadRestrictions::SetIOAllowed(true);
    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        base::Bind(base::IgnoreResult(&base::ThreadRestrictions::SetIOAllowed),
                   true));
  
  #if !defined(OS_IOS)
    if (RenderProcessHost::run_renderer_in_process())
      RenderProcessHostImpl::ShutDownInProcessRenderer();
  #endif
  
    if (parts_) {
      TRACE_EVENT0("shutdown",
                   "BrowserMainLoop::Subsystem:PostMainMessageLoopRun");
      parts_->PostMainMessageLoopRun();
    }
  
    trace_memory_controller_.reset();
    system_stats_monitor_.reset();
  
  #if !defined(OS_IOS)
    // Destroying the GpuProcessHostUIShims on the UI thread posts a task to
    // delete related objects on the GPU thread. This must be done before
    // stopping the GPU thread. The GPU thread will close IPC channels to renderer
    // processes so this has to happen before stopping the IO thread.
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GPUProcessHostShim");
      GpuProcessHostUIShim::DestroyAll();
    }
    // Cancel pending requests and prevent new requests.
    if (resource_dispatcher_host_) {
      TRACE_EVENT0("shutdown",
                   "BrowserMainLoop::Subsystem:ResourceDispatcherHost");
      resource_dispatcher_host_.get()->Shutdown();
    }
  
  #if defined(USE_AURA) || defined(OS_MACOSX)
    if (ShouldInitializeBrowserGpuChannelAndTransportSurface()) {
      TRACE_EVENT0("shutdown",
                   "BrowserMainLoop::Subsystem:ImageTransportFactory");
      ImageTransportFactory::Terminate();
    }
  #endif
  
  #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
    ZygoteHostImpl::GetInstance()->TearDownAfterLastChild();
  #endif  // defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
  
    // The device monitors are using |system_monitor_| as dependency, so delete
    // them before |system_monitor_| goes away.
    // On Mac and windows, the monitor needs to be destroyed on the same thread
    // as they were created. On Linux, the monitor will be deleted when IO thread
    // goes away.
  #if defined(OS_WIN)
    system_message_window_.reset();
  #elif defined(OS_MACOSX)
    device_monitor_mac_.reset();
  #endif
  #endif  // !defined(OS_IOS)
  
    // Must be size_t so we can subtract from it.
    for (size_t thread_id = BrowserThread::ID_COUNT - 1;
         thread_id >= (BrowserThread::UI + 1);
         --thread_id) {
      // Find the thread object we want to stop. Looping over all valid
      // BrowserThread IDs and DCHECKing on a missing case in the switch
      // statement helps avoid a mismatch between this code and the
      // BrowserThread::ID enumeration.
      //
      // The destruction order is the reverse order of occurrence in the
      // BrowserThread::ID list. The rationale for the order is as
      // follows (need to be filled in a bit):
      //
      //
      // - The IO thread is the only user of the CACHE thread.
      //
      // - The PROCESS_LAUNCHER thread must be stopped after IO in case
      //   the IO thread posted a task to terminate a process on the
      //   process launcher thread.
      //
      // - (Not sure why DB stops last.)
      switch (thread_id) {
        case BrowserThread::DB: {
          TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DBThread");
          ResetThread_DB(db_thread_.Pass());
          break;
        }
        case BrowserThread::FILE: {
          TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:FileThread");
  #if !defined(OS_IOS)
          // Clean up state that lives on or uses the file_thread_ before
          // it goes away.
          if (resource_dispatcher_host_)
            resource_dispatcher_host_.get()->save_file_manager()->Shutdown();
  #endif  // !defined(OS_IOS)
          ResetThread_FILE(file_thread_.Pass());
          break;
        }
        case BrowserThread::FILE_USER_BLOCKING: {
          TRACE_EVENT0("shutdown",
                        "BrowserMainLoop::Subsystem:FileUserBlockingThread");
          ResetThread_FILE_USER_BLOCKING(file_user_blocking_thread_.Pass());
          break;
        }
        case BrowserThread::PROCESS_LAUNCHER: {
          TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:LauncherThread");
          ResetThread_PROCESS_LAUNCHER(process_launcher_thread_.Pass());
          break;
        }
        case BrowserThread::CACHE: {
          TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:CacheThread");
          ResetThread_CACHE(cache_thread_.Pass());
          break;
        }
        case BrowserThread::IO: {
          TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IOThread");
          ResetThread_IO(io_thread_.Pass());
          break;
        }
        case BrowserThread::UI:
        case BrowserThread::ID_COUNT:
        default:
          NOTREACHED();
          break;
      }
    }
  
  #if !defined(OS_IOS)
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IndexedDBThread");
      ResetThread_IndexedDb(indexed_db_thread_.Pass());
    }
  #endif
  
    // Close the blocking I/O pool after the other threads. Other threads such
    // as the I/O thread may need to schedule work like closing files or flushing
    // data during shutdown, so the blocking pool needs to be available. There
    // may also be slow operations pending that will blcok shutdown, so closing
    // it here (which will block until required operations are complete) gives
    // more head start for those operations to finish.
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:ThreadPool");
      BrowserThreadImpl::ShutdownThreadPool();
    }
  
  #if !defined(OS_IOS)
    // Must happen after the IO thread is shutdown since this may be accessed from
    // it.
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GPUChannelFactory");
      if (BrowserGpuChannelHostFactory::instance())
        BrowserGpuChannelHostFactory::Terminate();
    }
  
    // Must happen after the I/O thread is shutdown since this class lives on the
    // I/O thread and isn't threadsafe.
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GamepadService");
      GamepadService::GetInstance()->Terminate();
    }
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:SensorService");
      DeviceInertialSensorService::GetInstance()->Shutdown();
    }
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:BatteryStatusService");
      BatteryStatusService::GetInstance()->Shutdown();
    }
    {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DeleteDataSources");
      URLDataManager::DeleteDataSources();
    }
  #endif  // !defined(OS_IOS)
  
    if (parts_) {
      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
      parts_->PostDestroyThreads();
    }
  }
  
  void BrowserMainLoop::StopStartupTracingTimer() {
    startup_trace_timer_.Stop();
  }
  
  void BrowserMainLoop::InitializeMainThread() {
    TRACE_EVENT0("startup", "BrowserMainLoop::InitializeMainThread");
    const char* kThreadName = "CrBrowserMain";
    base::PlatformThread::SetName(kThreadName);
    if (main_message_loop_)
      main_message_loop_->set_thread_name(kThreadName);
  
    // Register the main thread by instantiating it, but don't call any methods.
    main_thread_.reset(
        new BrowserThreadImpl(BrowserThread::UI, base::MessageLoop::current()));
  }
  
  int BrowserMainLoop::BrowserThreadsStarted() {
    TRACE_EVENT0("startup", "BrowserMainLoop::BrowserThreadsStarted");
  
  #if !defined(OS_IOS)
    indexed_db_thread_.reset(new base::Thread("IndexedDB"));
    indexed_db_thread_->Start();
  #endif
  
  #if defined(OS_ANDROID)
    // Up the priority of anything that touches with display tasks
    // (this thread is UI thread, and io_thread_ is for IPCs).
    io_thread_->SetPriority(base::kThreadPriority_Display);
    base::PlatformThread::SetThreadPriority(
        base::PlatformThread::CurrentHandle(),
        base::kThreadPriority_Display);
  #endif
  
  #if !defined(OS_IOS)
    HistogramSynchronizer::GetInstance();
  
    bool initialize_gpu_data_manager = true;
  #if defined(OS_ANDROID)
    // On Android, GLSurface::InitializeOneOff() must be called before initalizing
    // the GpuDataManagerImpl as it uses the GL bindings. crbug.com/326295
    if (!gfx::GLSurface::InitializeOneOff()) {
      LOG(ERROR) << "GLSurface::InitializeOneOff failed";
      initialize_gpu_data_manager = false;
    }
  #endif
  
    // Initialize the GpuDataManager before we set up the MessageLoops because
    // otherwise we'll trigger the assertion about doing IO on the UI thread.
    if (initialize_gpu_data_manager)
      GpuDataManagerImpl::GetInstance()->Initialize();
  
    bool always_uses_gpu = true;
    bool established_gpu_channel = false;
  #if defined(USE_AURA) || defined(OS_MACOSX)
    if (ShouldInitializeBrowserGpuChannelAndTransportSurface()) {
      established_gpu_channel = true;
      if (!GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor()) {
        established_gpu_channel = always_uses_gpu = false;
      }
      BrowserGpuChannelHostFactory::Initialize(established_gpu_channel);
      ImageTransportFactory::Initialize();
  #if defined(USE_AURA)
      if (aura::Env::GetInstance()) {
        aura::Env::GetInstance()->set_context_factory(
            content::GetContextFactory());
      }
  #endif
    }
  #elif defined(OS_ANDROID)
    established_gpu_channel = true;
    BrowserGpuChannelHostFactory::Initialize(established_gpu_channel);
  #endif
  
  #if defined(OS_LINUX) && defined(USE_UDEV)
    device_monitor_linux_.reset(new DeviceMonitorLinux());
  #elif defined(OS_MACOSX)
    device_monitor_mac_.reset(new DeviceMonitorMac());
  #endif
  
    // RDH needs the IO thread to be created
    {
      TRACE_EVENT0("startup",
        "BrowserMainLoop::BrowserThreadsStarted:InitResourceDispatcherHost");
      resource_dispatcher_host_.reset(new ResourceDispatcherHostImpl());
    }
  
    // MediaStreamManager needs the IO thread to be created.
    {
      TRACE_EVENT0("startup",
        "BrowserMainLoop::BrowserThreadsStarted:InitMediaStreamManager");
      media_stream_manager_.reset(new MediaStreamManager(audio_manager_.get()));
    }
  
    {
      TRACE_EVENT0("startup",
        "BrowserMainLoop::BrowserThreadsStarted:InitSpeechRecognition");
      speech_recognition_manager_.reset(new SpeechRecognitionManagerImpl(
          audio_manager_.get(), media_stream_manager_.get()));
    }
  
    {
      TRACE_EVENT0(
          "startup",
          "BrowserMainLoop::BrowserThreadsStarted::InitUserInputMonitor");
      user_input_monitor_ = media::UserInputMonitor::Create(
          io_thread_->message_loop_proxy(), main_thread_->message_loop_proxy());
    }
  
    {
      TRACE_EVENT0("startup",
                   "BrowserMainLoop::BrowserThreadsStarted::TimeZoneMonitor");
      time_zone_monitor_ = TimeZoneMonitor::Create();
    }
  
    // Alert the clipboard class to which threads are allowed to access the
    // clipboard:
    std::vector<base::PlatformThreadId> allowed_clipboard_threads;
    // The current thread is the UI thread.
    allowed_clipboard_threads.push_back(base::PlatformThread::CurrentId());
  #if defined(OS_WIN)
    // On Windows, clipboards are also used on the File or IO threads.
    allowed_clipboard_threads.push_back(file_thread_->thread_id());
    allowed_clipboard_threads.push_back(io_thread_->thread_id());
  #endif
    ui::Clipboard::SetAllowedThreads(allowed_clipboard_threads);
  
    // When running the GPU thread in-process, avoid optimistically starting it
    // since creating the GPU thread races against creation of the one-and-only
    // ChildProcess instance which is created by the renderer thread.
    if (GpuDataManagerImpl::GetInstance()->GpuAccessAllowed(NULL) &&
        !established_gpu_channel &&
        always_uses_gpu &&
        !parsed_command_line_.HasSwitch(switches::kSingleProcess) &&
        !parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
      TRACE_EVENT_INSTANT0("gpu", "Post task to launch GPU process",
                           TRACE_EVENT_SCOPE_THREAD);
      BrowserThread::PostTask(
          BrowserThread::IO, FROM_HERE, base::Bind(
              base::IgnoreResult(&GpuProcessHost::Get),
              GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
              CAUSE_FOR_GPU_LAUNCH_BROWSER_STARTUP));
    }
  
  #if defined(OS_MACOSX)
    ThemeHelperMac::GetInstance();
    SystemHotkeyHelperMac::GetInstance()->DeferredLoadSystemHotkeys();
    if (ShouldEnableBootstrapSandbox()) {
      TRACE_EVENT0("startup",
          "BrowserMainLoop::BrowserThreadsStarted:BootstrapSandbox");
      CHECK(GetBootstrapSandbox());
    }
  #endif  // defined(OS_MACOSX)
  
  #endif  // !defined(OS_IOS)
  
    return result_code_;
  }
  
  bool BrowserMainLoop::InitializeToolkit() {
    TRACE_EVENT0("startup", "BrowserMainLoop::InitializeToolkit");
    // TODO(evan): this function is rather subtle, due to the variety
    // of intersecting ifdefs we have.  To keep it easy to follow, there
    // are no #else branches on any #ifs.
    // TODO(stevenjb): Move platform specific code into platform specific Parts
    // (Need to add InitializeToolkit stage to BrowserParts).
    // See also GTK setup in EarlyInitialization, above, and associated comments.
  
  #if defined(OS_WIN)
    // Init common control sex.
    INITCOMMONCONTROLSEX config;
    config.dwSize = sizeof(config);
    config.dwICC = ICC_WIN95_CLASSES;
    if (!InitCommonControlsEx(&config))
      PLOG(FATAL);
  #endif
  
  #if defined(USE_AURA)
  
  #if defined(USE_X11)
    if (!gfx::GetXDisplay())
      return false;
  #endif
  
    // Env creates the compositor. Aura widgets need the compositor to be created
    // before they can be initialized by the browser.
    aura::Env::CreateInstance(true);
  #endif  // defined(USE_AURA)
  
    if (parts_)
      parts_->ToolkitInitialized();
  
    return true;
  }
  
  void BrowserMainLoop::MainMessageLoopRun() {
  #if defined(OS_ANDROID)
    // Android's main message loop is the Java message loop.
    NOTREACHED();
  #else
    DCHECK(base::MessageLoopForUI::IsCurrent());
    if (parameters_.ui_task)
      base::MessageLoopForUI::current()->PostTask(FROM_HERE,
                                                  *parameters_.ui_task);
  
    base::RunLoop run_loop;
    run_loop.Run();
  #endif
  }
  
  base::FilePath BrowserMainLoop::GetStartupTraceFileName(
      const base::CommandLine& command_line) const {
    base::FilePath trace_file = command_line.GetSwitchValuePath(
        switches::kTraceStartupFile);
    // trace_file = "none" means that startup events will show up for the next
    // begin/end tracing (via about:tracing or AutomationProxy::BeginTracing/
    // EndTracing, for example).
    if (trace_file == base::FilePath().AppendASCII("none"))
      return trace_file;
  
    if (trace_file.empty()) {
  #if defined(OS_ANDROID)
      TracingControllerAndroid::GenerateTracingFilePath(&trace_file);
  #else
      // Default to saving the startup trace into the current dir.
      trace_file = base::FilePath().AppendASCII("chrometrace.log");
  #endif
    }
  
    return trace_file;
  }
  
  void BrowserMainLoop::InitStartupTracing(
      const base::CommandLine& command_line) {
    DCHECK(is_tracing_startup_);
  
    startup_trace_file_ = GetStartupTraceFileName(parsed_command_line_);
  
    std::string delay_str = command_line.GetSwitchValueASCII(
        switches::kTraceStartupDuration);
    int delay_secs = 5;
    if (!delay_str.empty() && !base::StringToInt(delay_str, &delay_secs)) {
      DLOG(WARNING) << "Could not parse --" << switches::kTraceStartupDuration
          << "=" << delay_str << " defaulting to 5 (secs)";
      delay_secs = 5;
    }
  
    startup_trace_timer_.Start(FROM_HERE,
                               base::TimeDelta::FromSeconds(delay_secs),
                               this,
                               &BrowserMainLoop::EndStartupTracing);
  }
  
  void BrowserMainLoop::EndStartupTracing() {
    is_tracing_startup_ = false;
    TracingController::GetInstance()->DisableRecording(
        startup_trace_file_, base::Bind(&OnStoppedStartupTracing));
  }
  
  }  // namespace content
  