Change browser/page action default icon defined in manifest to support hidpi.

chrome/common/extensions/extension_icon_factory_delegate.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_COMMON_EXTENSIONS_EXTENSION_ICON_FACTORY_DELEGATE_H_
+#define CHROME_COMMON_EXTENSIONS_EXTENSION_ICON_FACTORY_DELEGATE_H_
+
+#include "chrome/common/extensions/extension_icon_set.h"
+
+namespace gfx {
+class ImageSkia;
+class Size;
+}
+
+// Used by code living in chrome/common/ to delegate icon creation when the icon
+// creation cannot be done from chrome/common/ (e.g. if the icon is loaded
+// asynchronously using ImageLoadingTracker).
+class ExtensionIconFactoryDelegate {
+ public:
+  virtual ~ExtensionIconFactoryDelegate() {}
+
+  // Creates an icon of |desired_size| in device independent pixels, whose
+  // image representations are selected from the set of bitmaps whose paths are
+  // in |icon_set|.
+  // The icon will be created asyncronously, so |ExtensionIconFactoryDelegate|
+  // implementation will have to be observable for the created icon changes by
+  // the code that uses the icon.
+  virtual gfx::ImageSkia GetIcon(const ExtensionIconSet* icon_set,
+                                 const gfx::Size& desired_size) = 0;
+};
+
+#endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_ICON_FACTORY_DELEGATE_H_