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

chrome/browser/extensions/extension_action_icon_factory.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_EXTENSIONS_EXTENSION_ACTION_ICON_FACTORY_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_ACTION_ICON_FACTORY_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/extensions/extension_icon_image.h"
+#include "chrome/common/extensions/extension_icon_factory_delegate.h"
+
+class ExtensionIconSet;
+
+namespace extensions {
+class Extension;
+}
+
+// Used to creates new image skia icon for extension actions using
+// extensions::IconImage.
+// It observes underlaying IconImage and notifies its own observer when the icon
+// image changes.
+class ExtensionActionIconFactory : public extensions::IconImage::Observer,
+                                   public ExtensionIconFactoryDelegate {
+ public:
+  class Observer {
+   public:
+    virtual ~Observer() {}
+    // Called when the underlying image changes.
+    virtual void OnIconUpdated() = 0;
+  };
+
+  // Observer should outlive this.
+  ExtensionActionIconFactory(const extensions::Extension* extension,
+                             Observer* observer);
+  virtual ~ExtensionActionIconFactory();
+
+  // extensions::IconImage override.
+  virtual void OnExtensionIconImageChanged(
+      extensions::IconImage* image) OVERRIDE;
+
+  // ExtensionIconFactoryDelegate override.
+  // Returns icon created using extensions::IconImage from |icon_set| with the
+  // desired size. If the previous requested icon had the same icon set, that
+  // icon is returned. Else, new IconImage is created.
+  // It is assumed that request with the same |icon_set| also have the same
+  // |desired_size|.
+  // The icon can be loaded asynchronously. In that case the observer will be
+  // notified when the icon gets updated.
+  virtual gfx::ImageSkia GetIcon(const ExtensionIconSet* icon_set,
+                                 int desired_size) OVERRIDE;
+
+ private:
+  const extensions::Extension* extension_;
+  Observer* observer_;
+  const ExtensionIconSet* last_icon_set_;
+  int last_size_;
+  scoped_ptr<extensions::IconImage> icon_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionActionIconFactory);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_ACTION_ICON_FACTORY_H_