Issue trace events to gather repaint information.

Source/core/rendering/RenderLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 390 matching lines @@
         if (usesCompositedScrolling() || onlyScrolledCompositedLayers)
             requiresRepaint = false;
     }
 
     // Just schedule a full repaint of our object.
     if (requiresRepaint) {
         if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled()) {
             if (m_box->frameView()->isInPerformLayout())
                 m_box->setShouldDoFullRepaintAfterLayout(true);
             else
-                m_box->repaintUsingContainer(repaintContainer, pixelSnappedIntRect(layer()->renderer()->newRepaintRect()));
+                m_box->repaintUsingContainer(repaintContainer, pixelSnappedIntRect(layer()->renderer()->newRepaintRect()), InvalidationScroll);
         } else {
-            m_box->repaintUsingContainer(repaintContainer, pixelSnappedIntRect(layer()->repainter().repaintRect()));
+            m_box->repaintUsingContainer(repaintContainer, pixelSnappedIntRect(layer()->repainter().repaintRect()), InvalidationScroll);
         }
     }
 
     // Schedule the scroll DOM event.
     if (m_box->node())
         m_box->node()->document().enqueueScrollEventForNode(m_box->node());
 
     if (AXObjectCache* cache = m_box->document().existingAXObjectCache())
         cache->handleScrollPositionChanged(m_box);
 
@@ skipping 1121 matching lines @@
 void RenderLayerScrollableArea::setForceNeedsCompositedScrolling(ForceNeedsCompositedScrollingMode mode)
 {
     if (m_forceNeedsCompositedScrolling == mode)
         return;
 
     m_forceNeedsCompositedScrolling = mode;
     layer()->didUpdateNeedsCompositedScrolling();
 }
 
 } // Namespace WebCore