Reset clip parent in CompositedLayerMapping::updateClipParent

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1799 matching lines @@
 
     // Only the topmost layer has a scroll parent. All other layers have a null scroll parent.
     if (layer != topmostLayer)
         clipParent = 0;
 
     scrollingCoordinator->updateClipParentForGraphicsLayer(layer, clipParent);
 }
 
 void CompositedLayerMapping::updateClipParent(const PaintLayer* scrollParent)
 {
-    if (owningLayerClippedByLayerNotAboveCompositedAncestor(scrollParent))
-        return;
-
-    const PaintLayer* clipParent = m_owningLayer.clipParent();
-    if (clipParent)
-        clipParent = clipParent->enclosingLayerWithCompositedLayerMapping(IncludeSelf);
+    const PaintLayer* clipParent = nullptr;
+    if (!owningLayerClippedByLayerNotAboveCompositedAncestor(scrollParent)) {
+        clipParent = m_owningLayer.clipParent();
+        if (clipParent)
+            clipParent = clipParent->enclosingLayerWithCompositedLayerMapping(IncludeSelf);
+    }
 
     if (ScrollingCoordinator* scrollingCoordinator = scrollingCoordinatorFromLayer(m_owningLayer)) {
         GraphicsLayer* topmostLayer = childForSuperlayers();
         updateClipParentForGraphicsLayer(m_squashingContainmentLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
         updateClipParentForGraphicsLayer(m_ancestorClippingLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
         updateClipParentForGraphicsLayer(m_graphicsLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
     }
 }
 
 bool CompositedLayerMapping::updateSquashingLayers(bool needsSquashingLayers)
@@ skipping 926 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink