Remove background obscuration checks.

sky/engine/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 542 matching lines @@
 bool FrameView::isTransparent() const
 {
     return m_isTransparent;
 }
 
 void FrameView::setTransparent(bool isTransparent)
 {
     m_isTransparent = isTransparent;
 }
 
-bool FrameView::hasOpaqueBackground() const
-{
-    return !m_isTransparent && !m_baseBackgroundColor.hasAlpha();
-}
-
 Color FrameView::baseBackgroundColor() const
 {
     return m_baseBackgroundColor;
 }
 
 void FrameView::setBaseBackgroundColor(const Color& backgroundColor)
 {
     m_baseBackgroundColor = backgroundColor;
 }
 
@@ skipping 336 matching lines @@
     totalObjects = 0;
 
     for (RenderObject* o = root; o; o = o->nextInPreOrder(root)) {
         ++totalObjects;
         if (o->needsLayout())
             ++needsLayoutObjects;
     }
 }
 
 } // namespace blink