content: Cleanup class/struct forward declarations

content/browser/renderer_host/render_widget_host_view_base.h

 // Copyright (c) 2012 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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 49 matching lines @@
 namespace ui {
 class LatencyInfo;
 struct DidOverscrollParams;
 }
 
 namespace content {
 class BrowserAccessibilityDelegate;
 class BrowserAccessibilityManager;
 class RenderWidgetHostImpl;
 class RenderWidgetHostViewBaseObserver;
-class SyntheticGesture;
 class SyntheticGestureTarget;
 class TextInputManager;
 class WebCursor;
 struct NativeWebKeyboardEvent;
 struct TextInputState;
 
 // Basic implementation shared by concrete RenderWidgetHostView subclasses.
 class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
                                                 public IPC::Listener {
  public:
@@ skipping 419 matching lines @@
   base::ObserverList<RenderWidgetHostViewBaseObserver> observers_;
 
   base::WeakPtrFactory<RenderWidgetHostViewBase> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewBase);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_