Clear the groupedMapping parameter in layers when removed from the group

Source/core/paint/DeprecatedPaintLayer.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 143 matching lines @@
     if (layoutObject()->frame() && layoutObject()->frame()->page()) {
         if (ScrollingCoordinator* scrollingCoordinator = layoutObject()->frame()->page()->scrollingCoordinator())
             scrollingCoordinator->willDestroyLayer(this);
     }
 
     removeFilterInfoIfNeeded();
 
     if (groupedMapping()) {
         DisableCompositingQueryAsserts disabler;
         groupedMapping()->removeLayerFromSquashingGraphicsLayer(this);
-        setGroupedMapping(0);
+        setGroupedMapping(0, true);
     }
 
     // Child layers will be deleted by their corresponding layout objects, so
     // we don't need to delete them ourselves.
 
     clearCompositedDeprecatedPaintLayerMapping(true);
 
     if (m_reflectionInfo)
         m_reflectionInfo->destroy();
 
@@ skipping 2170 matching lines @@
         if (DeprecatedPaintLayer* compositingParent = enclosingLayerWithCompositedDeprecatedPaintLayerMapping(ExcludeSelf))
             compositingParent->compositedDeprecatedPaintLayerMapping()->setNeedsGraphicsLayerUpdate(GraphicsLayerUpdateSubtree);
     }
 
     m_compositedDeprecatedPaintLayerMapping.clear();
 
     if (!layerBeingDestroyed)
         updateOrRemoveFilterEffectBuilder();
 }
 
-void DeprecatedPaintLayer::setGroupedMapping(CompositedDeprecatedPaintLayerMapping* groupedMapping, bool layerBeingDestroyed)
+void DeprecatedPaintLayer::setGroupedMapping(CompositedDeprecatedPaintLayerMapping* groupedMapping, bool issueInvalidations)
 {
     if (groupedMapping == m_groupedMapping)
         return;
 
-    if (!layerBeingDestroyed && m_groupedMapping) {
+    if (issueInvalidations && m_groupedMapping) {
         m_groupedMapping->setNeedsGraphicsLayerUpdate(GraphicsLayerUpdateSubtree);
         m_groupedMapping->removeLayerFromSquashingGraphicsLayer(this);
     }
     m_groupedMapping = groupedMapping;
-    if (!layerBeingDestroyed && m_groupedMapping)
+    if (issueInvalidations && m_groupedMapping)
         m_groupedMapping->setNeedsGraphicsLayerUpdate(GraphicsLayerUpdateSubtree);
 }
 
 bool DeprecatedPaintLayer::hasCompositedMask() const
 {
     return m_compositedDeprecatedPaintLayerMapping && m_compositedDeprecatedPaintLayerMapping->hasMaskLayer();
 }
 
 bool DeprecatedPaintLayer::hasCompositedClippingMask() const
 {
@@ skipping 365 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif