Adding OverrideStringResource API to ResourceBundle.

ui/base/resource/resource_bundle.h

 // 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.
 
 #ifndef UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 #define UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_piece.h"
 #include "build/build_config.h"
 #include "ui/base/layout.h"
 #include "ui/base/ui_base_export.h"
 #include "ui/gfx/font_list.h"
@@ skipping 216 matching lines @@
   const gfx::Font& GetFont(FontStyle style);
 
   // Resets and reloads the cached fonts.  This is useful when the fonts of the
   // system have changed, for example, when the locale has changed.
   void ReloadFonts();
 
   // Overrides the path to the pak file from which the locale resources will be
   // loaded. Pass an empty path to undo.
   void OverrideLocalePakForTest(const base::FilePath& pak_path);
 
+  // Overrides a localized string resource with the given string. If no delegate
+  // is present, the |string| will be returned when getting the localized string
+  // |message_id|. If |ReloadLocaleResources| is called, all overrides are
+  // cleared. This is intended to be used in conjunction with field trials and
+  // the variations service to experiment with different UI strings. This method
+  // is not thread safe!
+  void OverrideLocaleStringResource(int message_id,

[grt (UTC plus 2), 2014/07/03 19:00:34]

how will this be used so that it's safe?

[jwd, 2014/07/11 19:23:27]

It's only used in prethreadcreate...
It's only called though SetupMetricsAndFieldTrials which is called from
ChromeBrowserMainParts::PreCreateThreadsImpl.

+                                    const base::string16& string);
+
   // Returns the full pathname of the locale file to load.  May return an empty
   // string if no locale data files are found and |test_file_exists| is true.
   // Used on Android to load the local file in the browser process and pass it
   // to the sandboxed renderer process.
   base::FilePath GetLocaleFilePath(const std::string& app_locale,
                                    bool test_file_exists);
 
   // Returns the maximum scale factor currently loaded.
   // Returns SCALE_FACTOR_100P if no resource is loaded.
   ScaleFactor GetMaxScaleFactor() const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(ResourceBundleTest, DelegateGetPathForLocalePack);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundleTest, DelegateGetImageNamed);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundleTest, DelegateGetNativeImageNamed);
 
   friend class ResourceBundleImageTest;
   friend class ResourceBundleTest;
 
   class ResourceBundleImageSource;
   friend class ResourceBundleImageSource;
 
+  typedef base::hash_map<int, base::string16> IdToStringMap;
+
   // Ctor/dtor are private, since we're a singleton.
   explicit ResourceBundle(Delegate* delegate);
   ~ResourceBundle();
 
   // Shared initialization.
   static void InitSharedInstance(Delegate* delegate);
 
   // Free skia_images_.
   void FreeImages();
 
@@ skipping 104 matching lines @@
   scoped_ptr<gfx::FontList> small_font_list_;
   scoped_ptr<gfx::FontList> small_bold_font_list_;
   scoped_ptr<gfx::FontList> medium_font_list_;
   scoped_ptr<gfx::FontList> medium_bold_font_list_;
   scoped_ptr<gfx::FontList> large_font_list_;
   scoped_ptr<gfx::FontList> large_bold_font_list_;
   scoped_ptr<gfx::FontList> web_font_list_;
 
   base::FilePath overridden_pak_path_;
 
+  IdToStringMap overridden_locale_strings_;
+
   DISALLOW_COPY_AND_ASSIGN(ResourceBundle);
 };
 
 }  // namespace ui
 
 // TODO(beng): Someday, maybe, get rid of this.
 using ui::ResourceBundle;
 
 #endif  // UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_