Load 2x resources on demand

chrome/browser/themes/browser_theme_pack.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 CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_
 #define CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 163 matching lines @@
 
   // Creates the semi-transparent tab background images, putting the results
   // in |images|. Must be called after GenerateFrameImages().
   void CreateTabBackgroundImages(ImageCache* images) const;
 
   // Takes all the SkBitmaps in |images|, encodes them as PNGs and places
   // them in |reencoded_images|.
   void RepackImages(const ImageCache& images,
                     RawImages* reencoded_images) const;
 
-  // Generates image reps for |scale_factors| for
-  // |prepared_images_on_ui_thread_| and |prepared_images_on_file_thread_|.
-  void GenerateImageReps(const std::vector<ui::ScaleFactor>& scale_factors);
-
   // Takes all images in |source| and puts them in |destination|, freeing any
   // image already in |destination| that |source| would overwrite.
   void MergeImageCaches(const ImageCache& source,
                         ImageCache* destination) const;
 
   // Copies images from |source| to |destination| such that the lifetimes of
   // the images in |destination| are not affected by the lifetimes of the
   // images in |source|.
   void CopyImagesTo(const ImageCache& source, ImageCache* destination) const;
 
@@ skipping 69 matching lines @@
   // Cache of images created in BuildFromExtension(). Once the theme pack is
   // created, this cache should only be accessed on the file thread. There
   // should be no IDs in |image_memory_| that are in |images_on_file_thread_|
   // or vice versa.
   ImageCache images_on_file_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserThemePack);
 };
 
 #endif  // CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_