Load the resources for max scale factor first.

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 "build/build_config.h"
 
 #include <map>
@@ skipping 248 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetImageNamed);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetNativeImageNamed);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateLoadDataResourceBytes);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetRawDataResource);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetLocalizedString);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetFont);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, GetRawDataResource);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LoadDataResourceBytes);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LocaleDataPakExists);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, GetImageNamed);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, FallbackToNone);
 
   class ResourceBundleImageSource;
   friend class ResourceBundleImageSource;
 
   // Ctor/dtor are private, since we're a singleton.
   explicit ResourceBundle(Delegate* delegate);
   ~ResourceBundle();
 
   // Free skia_images_.
   void FreeImages();
@@ skipping 30 matching lines @@
   // Returns false if the resource does not exist.
   //
   // If the call succeeds, |fell_back_to_1x| indicates whether Chrome's custom
   // csCl PNG chunk is present (added by GRIT if it falls back to a 100% image).
   bool LoadBitmap(const ResourceHandle& data_handle,
                   int resource_id,
                   SkBitmap* bitmap,
                   bool* fell_back_to_1x) const;
 
   // Fills the |bitmap| given the |resource_id| and |scale_factor|.
-  // Returns false if the resource does not exist.
+  // Returns false if the resource does not exist. This may fall back to
+  // the data pack with SCALE_FACTOR_NONE, and when this happens,
+  // |scale_factor| will be set to SCALE_FACTOR_100P.
   bool LoadBitmap(int resource_id,
-                  ScaleFactor scale_factor,
+                  ScaleFactor* scale_factor,
                   SkBitmap* bitmap,
                   bool* fell_back_to_1x) const;
 
   // Returns an empty image for when a resource cannot be loaded. This is a
   // bright red bitmap.
   gfx::Image& GetEmptyImage();
 
   const FilePath& GetOverriddenPakPath();
 
   // This pointer is guaranteed to outlive the ResourceBundle instance and may
@@ skipping 34 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_