[Media Router] Implement MediaRouterAction + MediaRouterUI tests.

chrome/browser/ui/toolbar/media_router_action.h

 // Copyright 2015 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_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 #define CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 
 // The class for the Media Router component action that will be shown in
@@ skipping 17 matching lines @@
   bool WantsToRun(content::WebContents* web_contents) const override;
   bool HasPopup(content::WebContents* web_contents) const override;
   void HidePopup() override;
   gfx::NativeView GetPopupNativeView() override;
   ui::MenuModel* GetContextMenu() override;
   bool CanDrag() const override;
   bool ExecuteAction(bool by_user) override;
   void UpdateState() override;
 
  private:
+  content::WebContents* GetMediaRouterDialog() const;

[Peter Kasting, 2015/06/04 00:17:52]

Const functions may not return non-const pointers.  Return a const pointer, or
if that's impossible make the function non-const.

[imcheng (use chromium acct), 2015/06/04 01:04:20]

Removed this function since it is not used.

+
   const std::string id_;
   const base::string16 name_;
 
   // Cached icons.
   gfx::Image media_router_idle_icon_;
 
   ToolbarActionViewDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterAction);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_