Turn off the old compositing path for SPv2.

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/compositing/PaintArtifactCompositor.h"
 
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/playback/display_item_list.h"
@@ skipping 424 matching lines @@
     return nodeA;
 }
 
 int PropertyTreeManager::switchToEffectNode(const EffectPaintPropertyNode& nextEffect)
 {
     const EffectPaintPropertyNode* ancestor = lowestCommonAncestor(currentEffectNode(), &nextEffect);
     while (currentEffectNode() != ancestor)
         m_effectStack.removeLast();
 
 #if DCHECK_IS_ON()
-    DCHECK(m_isFirstEffectEver || currentEffectNode()) << "Malformed effect tree. Nodes in the same property tree should have common root.";
+    DCHECK(m_isFirstEffectEver || currentEffectNode()) << "Malformed effect tree. Nodes in the same property tree should have common root. " << &nextEffect;
     m_isFirstEffectEver = false;
 #endif
     buildEffectNodesRecursively(&nextEffect);
 
     return compositorIdForCurrentEffectNode();
 }
 
 void PropertyTreeManager::buildEffectNodesRecursively(const EffectPaintPropertyNode* nextEffect)
 {
     if (nextEffect == currentEffectNode())
@@ skipping 91 matching lines @@
         if (m_extraDataForTestingEnabled)
             m_extraDataForTesting->contentLayers.append(layer);
     }
 
     // Mark the property trees as having been rebuilt.
     layerTree->property_trees()->sequence_number = kPropertyTreeSequenceNumber;
     layerTree->property_trees()->needs_rebuild = false;
 }
 
 } // namespace blink