chrome: Cleanup class/struct forward declarations

chrome/browser/media/router/presentation_service_delegate_impl.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_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/media/router/media_router.h"
 #include "chrome/browser/media/router/media_source.h"
 #include "chrome/browser/media/router/presentation_request.h"
 #include "chrome/browser/media/router/render_frame_host_id.h"
 #include "content/public/browser/presentation_service_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace content {
-class RenderFrameHost;
 class PresentationScreenAvailabilityListener;
 class WebContents;
 struct PresentationSessionInfo;
 struct PresentationSessionMessage;
 }  // namespace content
 
 namespace media_router {
 
 class MediaRoute;
-class MediaSinksObserver;
 class PresentationFrameManager;
 class RouteRequestResult;
 
 // Implementation of PresentationServiceDelegate that interfaces an instance of
 // WebContents with the Chrome Media Router. It uses the Media Router to handle
 // presentation API calls forwarded from PresentationServiceImpl. In addition,
 // it also provides default presentation URL that is required for creating
 // browser-initiated sessions.  It is scoped to the lifetime of a WebContents,
 // and is managed by the associated WebContents.
 class PresentationServiceDelegateImpl
@@ skipping 156 matching lines @@
   std::unique_ptr<PresentationFrameManager> frame_manager_;
 
   base::WeakPtrFactory<PresentationServiceDelegateImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PresentationServiceDelegateImpl);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_