Remove background obscuration checks.

sky/engine/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 436 matching lines @@
 {
     m_layoutState = &layoutState;
 }
 
 void RenderView::popLayoutState()
 {
     ASSERT(m_layoutState);
     m_layoutState = m_layoutState->next();
 }
 
-bool RenderView::backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const
-{
-    return m_frameView->hasOpaqueBackground();
-}
-
 // FIXME(sky): remove
 double RenderView::layoutViewportWidth() const
 {
     return viewWidth(IncludeScrollbars);
 }
 
 // FIXME(sky): remove
 double RenderView::layoutViewportHeight() const
 {
     return viewHeight(IncludeScrollbars);
 }
 
 void RenderView::addIFrame(RenderIFrame* iframe)
 {
     m_iframes.add(iframe);
 }
 
 void RenderView::removeIFrame(RenderIFrame* iframe)
 {
     m_iframes.remove(iframe);
 }
 
 void RenderView::updateIFramesAfterLayout()
 {
     for (auto& iframe: m_iframes)
         iframe->updateWidgetBounds();
 }
 
 } // namespace blink