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 "chrome/browser/resources_util.h"
  
  #include <utility>
  
  #include "base/containers/hash_tables.h"
  #include "base/lazy_instance.h"
  #include "grit/theme_resources_map.h"
  #include "grit/ui_resources_map.h"
  
  #if defined(OS_CHROMEOS)
  #include "grit/ui_chromeos_resources_map.h"
  #endif
  
  namespace {
  
  // A wrapper class that holds a hash_map between resource strings and resource
  // ids.  This is done so we can use base::LazyInstance which takes care of
  // thread safety in initializing the hash_map for us.
  class ThemeMap {
   public:
    typedef base::hash_map<std::string, int> StringIntMap;
  
    ThemeMap() {
      for (size_t i = 0; i < kThemeResourcesSize; ++i)
        id_map_[kThemeResources[i].name] = kThemeResources[i].value;
      for (size_t i = 0; i < kUiResourcesSize; ++i)
        id_map_[kUiResources[i].name] = kUiResources[i].value;
  #if defined(OS_CHROMEOS)
      for (size_t i = 0; i < kUiChromeosResourcesSize; ++i)
        id_map_[kUiChromeosResources[i].name] = kUiChromeosResources[i].value;
  #endif
    }
  
    int GetId(const std::string& resource_name) {
      StringIntMap::const_iterator it = id_map_.find(resource_name);
      if (it == id_map_.end())
        return -1;
      return it->second;
    }
  
   private:
    StringIntMap id_map_;
  };
  
  static base::LazyInstance<ThemeMap> g_theme_ids = LAZY_INSTANCE_INITIALIZER;
  
  }  // namespace
  
  int ResourcesUtil::GetThemeResourceId(const std::string& resource_name) {
    return g_theme_ids.Get().GetId(resource_name);
  }
  