Merge 92030 - [chromium] Only force slow scrolling for iframes under --force-compositing-mode

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 1133 matching lines @@
 }
 
 bool FrameView::useSlowRepaints() const
 {
     if (m_useSlowRepaints || m_slowRepaintObjectCount > 0 || (platformWidget() && m_fixedObjectCount > 0) || m_isOverlapped || !m_contentIsOpaque)
         return true;
 
 #if PLATFORM(CHROMIUM)
     // The chromium compositor does not support scrolling a non-composited frame within a composited page through
     // the fast scrolling path, so force slow scrolling in that case.
-    if (!isEnclosedInCompositingLayer() && m_frame->page() && m_frame->page()->mainFrame()->view()->hasCompositedContent())
+    if (m_frame->ownerElement() && !hasCompositedContent() && m_frame->page() && m_frame->page()->mainFrame()->view()->hasCompositedContent())
         return true;
 #endif
 
     if (FrameView* parentView = parentFrameView())
         return parentView->useSlowRepaints();
 
     return false;
 }
 
 bool FrameView::useSlowRepaintsIfNotOverlapped() const
@@ skipping 1767 matching lines @@
 }
     
 AXObjectCache* FrameView::axObjectCache() const
 {
     if (frame() && frame()->document() && frame()->document()->axObjectCacheExists())
         return frame()->document()->axObjectCache();
     return 0;
 }
     
 } // namespace WebCore