content: Cleanup class/struct forward declarations

content/test/test_frame_navigation_observer.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_TEST_TEST_FRAME_NAVIGATION_OBSERVER_H_
 #define CONTENT_TEST_TEST_FRAME_NAVIGATION_OBSERVER_H_
 
 #include <memory>
 #include <set>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/test/test_utils.h"
 
 class GURL;
 
 namespace content {
 class FrameTreeNode;
-class RenderFrameHostImpl;
 class WebContents;
-struct LoadCommittedDetails;
 
 // For content_browsertests, which run on the UI thread, run a second
 // MessageLoop and quit when the navigation in a specific frame (and all of its
 // subframes) has completed loading.
 class TestFrameNavigationObserver : public WebContentsObserver {
  public:
   // Create and register a new TestFrameNavigationObserver which will track
   // navigations performed in the specified |node| of the frame tree.
   explicit TestFrameNavigationObserver(FrameTreeNode* node);
 
@@ skipping 34 matching lines @@
 
   // The MessageLoopRunner used to spin the message loop.
   scoped_refptr<MessageLoopRunner> message_loop_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(TestFrameNavigationObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_FRAME_NAVIGATION_OBSERVER_H_