[MediaRouter] Moved the code useful for Android to MediaRouterDialogController

chrome/browser/media/android/router/media_router_dialog_controller_android.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_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_
 #define CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_
 
 #include "base/macros.h"
 #include "chrome/browser/media/router/media_router_dialog_controller.h"
-#include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace media_router {
 
 // Android implementation of the MediaRouterDialogController.
 class MediaRouterDialogControllerAndroid
     : public content::WebContentsUserData<MediaRouterDialogControllerAndroid>,
       public MediaRouterDialogController {
  public:
   ~MediaRouterDialogControllerAndroid() override;
 
   static MediaRouterDialogControllerAndroid* GetOrCreateForWebContents(
       content::WebContents* web_contents);
 
-  // MediaRouterDialogController implementation.
-  bool ShowMediaRouterDialogForPresentation(
-      scoped_ptr<CreatePresentationSessionRequest> request) override;
+  // MediaRouterDialogController:
+  bool IsShowingMediaRouterDialog() override;
 
  private:
   friend class content::WebContentsUserData<MediaRouterDialogControllerAndroid>;
 
   // Use MediaRouterDialogControllerAndroid::CreateForWebContents() to create an
   // instance.
   explicit MediaRouterDialogControllerAndroid(
       content::WebContents* web_contents);
 
-  base::ThreadChecker thread_checker_;
+  // MediaRouterDialogController:
+  void CreateMediaRouterDialog() override;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterDialogControllerAndroid);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_