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"
+
+class ExtensionAction;
+class ExtensionIconSet;
+
+namespace extensions {
+class Extension;
+}
+
+// Used to get an icon to be used in the UI for an extension action.
+// If the extension action icon is the default icon defined in the extension's
+// manifest, it is loaded using extensions::IconImage. This icon can be loaded
+// asynchronously. The factory observes underlying IconImage and notifies its
+// own observer when the icon image changes.
+class ExtensionActionIconFactory : public extensions::IconImage::Observer {
+ public:
+  class Observer {
+   public:
+    virtual ~Observer() {}
+    // Called when the underlying icon image changes.
+    virtual void OnIconUpdated() = 0;
+  };
+
+  // Observer should outlive this.
+  ExtensionActionIconFactory(const extensions::Extension* extension,
+                             const ExtensionAction* action,
+                             Observer* observer);
+  virtual ~ExtensionActionIconFactory();
+
+  // extensions::IconImage override.
+  virtual void OnExtensionIconImageChanged(
+      extensions::IconImage* image) OVERRIDE;
+
+  // Gets the extension action icon for the tab.
+  // If there is an icon set using |SetIcon|, that icon is returned.
+  // Else, if there is a default icon set for the extension action, the icon is
+  // created using IconImage. Observer is triggered wheniever the icon gets
+  // updated.
+  // Else, extension favicon is returned.
+  // In all cases, action's attention and animation icon transformations are
+  // applied on the icon.
+  gfx::Image GetIcon(int tab_id);
+
+ private:
+  // Gets the icon that should be returned by |GetIcon| (without the attention
+  // and animation transformations).
+  gfx::ImageSkia GetBaseIconFromAction(int tab_id);
+
+  const extensions::Extension* extension_;
+  const ExtensionAction* action_;
+  Observer* observer_;
+  // Underlying icon image for the default icon.
+  scoped_ptr<extensions::IconImage> default_icon_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionActionIconFactory);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_ACTION_ICON_FACTORY_H_