Fix layering violations in WebFrameWidget.

content/renderer/render_frame_impl.cc

 // Copyright 2013 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.
 
 #include "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 4514 matching lines @@
 
 void RenderFrameImpl::WasHidden() {
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WasHidden());
 
 #if defined(ENABLE_PLUGINS)
   for (auto* plugin : active_pepper_instances_)
     plugin->PageVisibilityChanged(false);
 #endif  // ENABLE_PLUGINS
 
   if (GetWebFrame()->frameWidget()) {
-    static_cast<blink::WebFrameWidget*>(GetWebFrame()->frameWidget())
-        ->setVisibilityState(visibilityState());
+    GetWebFrame()->frameWidget()->setVisibilityState(visibilityState());
   }
 }
 
 void RenderFrameImpl::WasShown() {
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WasShown());
 
 #if defined(ENABLE_PLUGINS)
   for (auto* plugin : active_pepper_instances_)
     plugin->PageVisibilityChanged(true);
 #endif  // ENABLE_PLUGINS
 
   if (GetWebFrame()->frameWidget()) {
-    static_cast<blink::WebFrameWidget*>(GetWebFrame()->frameWidget())
-        ->setVisibilityState(visibilityState());
+    GetWebFrame()->frameWidget()->setVisibilityState(visibilityState());
   }
 }
 
 void RenderFrameImpl::WidgetWillClose() {
   FOR_EACH_OBSERVER(RenderFrameObserver, observers_, WidgetWillClose());
 }
 
 bool RenderFrameImpl::IsMainFrame() {
   return is_main_frame_;
 }
@@ skipping 1793 matching lines @@
   // event target. Potentially a Pepper plugin will receive the event.
   // In order to tell whether a plugin gets the last mouse event and which it
   // is, we set |pepper_last_mouse_event_target_| to null here. If a plugin gets
   // the event, it will notify us via DidReceiveMouseEvent() and set itself as
   // |pepper_last_mouse_event_target_|.
   pepper_last_mouse_event_target_ = nullptr;
 #endif
 }
 
 }  // namespace content