Disable clipping on root scroller's ancestors.

third_party/WebKit/Source/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 2620 matching lines @@
 
             DCHECK(lifecycle().state() >= DocumentLifecycle::CompositingClean);
 
             if (targetState >= DocumentLifecycle::PrePaintClean) {
                 if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
                     invalidateTreeIfNeededRecursive();
 
                 if (view.compositor()->inCompositingMode())
                     scrollingCoordinator()->updateAfterCompositingChangeIfNeeded();
 
-                m_frame->document()->rootScrollerController()->didUpdateCompositing();
                 updateCompositedSelectionIfNeeded();
             }
         }
 
         if (targetState >= DocumentLifecycle::PrePaintClean) {
             if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
                 updatePaintProperties();
         }
 
         if (targetState == DocumentLifecycle::PaintClean) {
@@ skipping 1701 matching lines @@
 }
 
 bool FrameView::canThrottleRendering() const
 {
     if (!RuntimeEnabledFeatures::renderingPipelineThrottlingEnabled())
         return false;
     return m_subtreeThrottled || (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
 } // namespace blink