Slimming Paint phase 2 compositing algorithm plumbing

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 2191 matching lines @@
     }
 
     if (!m_compositedDeprecatedPaintLayerMapping)
         return NotComposited;
 
     return PaintsIntoOwnBacking;
 }
 
 bool DeprecatedPaintLayer::isAllowedToQueryCompositingState() const
 {
-    if (gCompositingQueryMode == CompositingQueriesAreAllowed)
+    if (gCompositingQueryMode == CompositingQueriesAreAllowed || RuntimeEnabledFeatures::slimmingPaintV2Enabled())
         return true;
     return layoutObject()->document().lifecycle().state() >= DocumentLifecycle::InCompositingUpdate;
 }
 
 CompositedDeprecatedPaintLayerMapping* DeprecatedPaintLayer::compositedDeprecatedPaintLayerMapping() const
 {
     ASSERT(isAllowedToQueryCompositingState());
     return m_compositedDeprecatedPaintLayerMapping.get();
 }
 
@@ skipping 437 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif