Add GetAppDefaultIcon() to AppDelegate

apps/app_delegate.h

 // Copyright 2014 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 APPS_APP_DELEGATE_H_
 #define APPS_APP_DELEGATE_H_
 
 #include "content/public/common/media_stream_request.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/window_open_disposition.h"
+#include "ui/gfx/image/image_skia.h"
 
 namespace content {
 class BrowserContext;
 class ColorChooser;
 struct FileChooserParams;
 struct OpenURLParams;
 class WebContents;
 }
 
 namespace extensions {
@@ skipping 32 matching lines @@
       content::WebContents* web_contents,
       SkColor initial_color) = 0;
   virtual void RunFileChooser(content::WebContents* tab,
                               const content::FileChooserParams& params) = 0;
   virtual void RequestMediaAccessPermission(
       content::WebContents* web_contents,
       const content::MediaStreamRequest& request,
       const content::MediaResponseCallback& callback,
       const extensions::Extension* extension) = 0;
   virtual int PreferredIconSize() = 0;
+  virtual gfx::ImageSkia GetAppDefaultIcon() = 0;
 
   // Web contents modal dialog support.
   virtual void SetWebContentsBlocked(content::WebContents* web_contents,
                                      bool blocked) = 0;
   virtual bool IsWebContentsVisible(content::WebContents* web_contents) = 0;
 };
 
 }  // namespace apps
 
 #endif  // APPS_APP_DELEGATE_H_