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 "net/base/platform_mime_util.h"
  
  #include <string>
  
  #include "base/logging.h"
  #include "build/build_config.h"
  
  #if defined(OS_ANDROID)
  #include "net/android/network_library.h"
  #else
  #include "base/nix/mime_util_xdg.h"
  #endif
  
  namespace net {
  
  #if defined(OS_ANDROID)
  bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
      const base::FilePath::StringType& ext,
      std::string* result) const {
    return android::GetMimeTypeFromExtension(ext, result);
  }
  #elif defined(OS_CHROMEOS)
  bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
      const base::FilePath::StringType& ext,
      std::string* result) const {
    return false;
  }
  #else
  bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
      const base::FilePath::StringType& ext,
      std::string* result) const {
    base::FilePath dummy_path("foo." + ext);
    std::string out = base::nix::GetFileMimeType(dummy_path);
  
    // GetFileMimeType likes to return application/octet-stream
    // for everything it doesn't know - ignore that.
    if (out == "application/octet-stream" || out.empty())
      return false;
  
    // GetFileMimeType returns image/x-ico because that's what's in the XDG
    // mime database. That database is the merger of the Gnome and KDE mime
    // databases. Apparently someone working on KDE in 2001 decided .ico
    // resolves to image/x-ico, whereas the rest of the world uses image/x-icon.
    // FWIW, image/vnd.microsoft.icon is the official IANA assignment.
    if (out == "image/x-ico")
      out = "image/x-icon";
  
    *result = out;
    return true;
  }
  
  #endif  // defined(OS_ANDROID)
  
  bool PlatformMimeUtil::GetPlatformPreferredExtensionForMimeType(
      const std::string& mime_type,
      base::FilePath::StringType* ext) const {
    // xdg_mime doesn't provide an API to get extension from a MIME type, so we
    // rely on the mappings hardcoded in mime_util.cc .
    return false;
  }
  
  void PlatformMimeUtil::GetPlatformExtensionsForMimeType(
      const std::string& mime_type,
      std::unordered_set<base::FilePath::StringType>* extensions) const {
    // xdg_mime doesn't provide an API to get extension from a MIME type, so we
    // rely on the mappings hardcoded in mime_util.cc .
  }
  
  }  // namespace net
  