Ensure that extension resources are loaded with the correct scaling applied on Windows.

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>
 
@@ skipping 238 matching lines @@
   // 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;
 
+ // Returns the scale to be used for loading an image. In all platforms except
+ // windows this is based on the scale factors of the loaded resource packs.
+ // On Windows this returns the device scale factor if high dpi is enabled.
+ // |scale_factor| contains the loaded scale factor for the image.
+ static float PlatformGetImageScale(ui::ScaleFactor scale_factor);

[sky, 2014/03/26 13:45:37]

This name is wordy (it was before, but when private it wasn't as much an issue).
How about GetScaleForImages()?

[ananta, 2014/03/26 19:40:10]

Removed this function. Moved this logic to ui::GetImageScale as per your
suggestion. Makes things simpler. I added a new function in layout.cc
GetImageScaleForScaleFactor which retains the old behavior. This is called from
resource_bundle.cc when images are being loaded.

+
  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;
@@ skipping 87 matching lines @@
   // Platform specific image scaling is done here. Currently only implemented
   // for Windows.
   // |image| is the bitmap to be scaled.
   // |loaded_image_scale| is the current scale of the bitmap.
   // |desired_scale| is the desired scale of the bitmap.
   // Returns the scaled bitmap or the original bitmap.
  static SkBitmap PlatformScaleImage(const SkBitmap& image,
                                     float loaded_image_scale,
                                     float desired_scale);
 
- // Returns the scale to be used for loading an image. In all platforms except
- // windows this is based on the scale factors of the loaded resource packs.
- // On Windows this returns the device scale factor if high dpi is enabled.
- float PlatformGetImageScale();
-
   // This pointer is guaranteed to outlive the ResourceBundle instance and may
   // be NULL.
   Delegate* delegate_;
 
   // Protects |images_| and font-related members.
   scoped_ptr<base::Lock> images_and_fonts_lock_;
 
   // Protects |locale_resources_data_|.
   scoped_ptr<base::Lock> locale_resources_data_lock_;
 
@@ skipping 27 matching lines @@
 
   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_