Remove NonCompositedContentHost -- Take 2

Source/core/page/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 2025 matching lines @@
 }
 
 bool FrameView::isTransparent() const
 {
     return m_isTransparent;
 }
 
 void FrameView::setTransparent(bool isTransparent)
 {
     m_isTransparent = isTransparent;
+    didChangeBackgroundOpaqueness();
 }
 
 bool FrameView::hasOpaqueBackground() const
 {
     return !m_isTransparent && !m_baseBackgroundColor.hasAlpha();
 }
 
 Color FrameView::baseBackgroundColor() const
 {
     return m_baseBackgroundColor;
 }
 
 void FrameView::setBaseBackgroundColor(const Color& backgroundColor)
 {
     if (!backgroundColor.isValid())
         m_baseBackgroundColor = Color::white;
     else
         m_baseBackgroundColor = backgroundColor;
 
+    didChangeBackgroundOpaqueness();
     recalculateScrollbarOverlayStyle();
 }
 
 void FrameView::updateBackgroundRecursively(const Color& backgroundColor, bool transparent)
 {
     for (Frame* frame = m_frame.get(); frame; frame = frame->tree()->traverseNext(m_frame.get())) {
         if (FrameView* view = frame->view()) {
             view->setTransparent(transparent);
             view->setBaseBackgroundColor(backgroundColor);
         }
     }
 }
 
+void FrameView::didChangeBackgroundOpaqueness()

[jamesr, 2013/05/28 23:03:52]

I think this function would be clearer if this just called to its
RenderLayerBacking (if it had one) and the RLB figured out if it was the root
layer and if so set the appropriate thing on its GraphicsLayer.

+{
+    if (!m_frame->page() || m_frame->page()->mainFrame() != m_frame.get())
+        return;
+    if (!renderView() || !renderView()->layer()->backing())
+        return;
+    if (GraphicsLayer* layer = renderView()->layer()->backing()->graphicsLayer())
+        layer->setContentsOpaque(hasOpaqueBackground());
+}
+
 bool FrameView::shouldUpdateWhileOffscreen() const
 {
     return m_shouldUpdateWhileOffscreen;
 }
 
 void FrameView::setShouldUpdateWhileOffscreen(bool shouldUpdateWhileOffscreen)
 {
     m_shouldUpdateWhileOffscreen = shouldUpdateWhileOffscreen;
 }
 
@@ skipping 1315 matching lines @@
 }
 
 AXObjectCache* FrameView::axObjectCache() const
 {
     if (frame() && frame()->document())
         return frame()->document()->existingAXObjectCache();
     return 0;
 }
     
 } // namespace WebCore