Merge 139024

Source/WebCore/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 749 matching lines @@
 {
     RenderView* root = rootRenderer(this);
     if (!root)
         return;
 
     RenderLayerCompositor* compositor = root->compositor();
     compositor->enableCompositingMode(true);
     compositor->updateCompositingLayers(CompositingUpdateAfterLayout);
 }
 
+bool FrameView::usesCompositedScrolling() const
+{
+    if (m_frame->settings() && m_frame->settings()->compositedScrollingForFramesEnabled()) {
+        RenderView* root = rootRenderer(this);
+        return root && root->compositor()->inForcedCompositingMode();
+    }
+    return false;
+}
+
 GraphicsLayer* FrameView::layerForHorizontalScrollbar() const
 {
     RenderView* root = rootRenderer(this);
     if (!root)
         return 0;
     return root->compositor()->layerForHorizontalScrollbar();
 }
 
 GraphicsLayer* FrameView::layerForVerticalScrollbar() const
 {
@@ skipping 3020 matching lines @@
 {
 #if USE(ACCELERATED_COMPOSITING)
     if (TiledBacking* tiledBacking = this->tiledBacking())
         tiledBacking->setScrollingPerformanceLoggingEnabled(flag);
 #else
     UNUSED_PARAM(flag);
 #endif
 }
 
 } // namespace WebCore