content: Cleanup class/struct forward declarations

content/child/blink_platform_impl.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 CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_
 #define CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 15 matching lines @@
 #include "content/child/webthemeengine_impl_default.h"
 #elif defined(OS_WIN)
 #include "content/child/webthemeengine_impl_win.h"
 #elif defined(OS_MACOSX)
 #include "content/child/webthemeengine_impl_mac.h"
 #elif defined(OS_ANDROID)
 #include "content/child/webthemeengine_impl_android.h"
 #endif
 
 namespace base {
-class MessageLoop;
 class WaitableEvent;
 }
 
 namespace blink {
 namespace scheduler {
 class WebThreadBase;
 }
 }
 
 namespace content {
 class BackgroundSyncProvider;
-class FlingCurveConfiguration;
 class NotificationDispatcher;
 class PushDispatcher;
 class ThreadSafeSender;
-class TraceLogObserverAdapter;
 class WebCryptoImpl;
 
 class CONTENT_EXPORT BlinkPlatformImpl
     : NON_EXPORTED_BASE(public blink::Platform) {
  public:
   BlinkPlatformImpl();
   explicit BlinkPlatformImpl(
       scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner);
   ~BlinkPlatformImpl() override;
 
@@ skipping 82 matching lines @@
   scoped_refptr<NotificationDispatcher> notification_dispatcher_;
   scoped_refptr<PushDispatcher> push_dispatcher_;
   std::unique_ptr<BackgroundSyncProvider> main_thread_sync_provider_;
 
   blink::scheduler::WebThreadBase* compositor_thread_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_