content: Cleanup class/struct forward declarations

content/test/test_render_frame.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 CONTENT_TEST_TEST_RENDER_FRAME_H_
 #define CONTENT_TEST_TEST_RENDER_FRAME_H_
 
 #include "base/macros.h"
 #include "content/renderer/render_frame_impl.h"
 
 namespace blink {
 class WebHistoryItem;
 }
 
 namespace content {
 
-class RenderViewImpl;
 struct CommonNavigationParams;
 struct RequestNavigationParams;
 struct StartNavigationParams;
 
 // A test class to use in RenderViewTests.
 class TestRenderFrame : public RenderFrameImpl {
  public:
   static RenderFrameImpl* CreateTestRenderFrame(
       const RenderFrameImpl::CreateParams& params);
   ~TestRenderFrame() override;
@@ skipping 19 matching lines @@
       const std::vector<blink::WebCompositionUnderline>& underlines);
 
  private:
   explicit TestRenderFrame(const RenderFrameImpl::CreateParams& params);
   DISALLOW_COPY_AND_ASSIGN(TestRenderFrame);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_RENDER_FRAME_H_