Move computation of RenderLayer::isUnclippedDescendant into CompositingPropertyUpdater

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 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.
@@ skipping 1672 matching lines @@
         exceptionState.throwDOMException(InvalidAccessError, renderer ? "The provided element's renderer is not a box." : "The provided element has no renderer.");
         return 0;
     }
 
     RenderLayer* layer = toRenderBox(renderer)->layer();
     if (!layer) {
         exceptionState.throwDOMException(InvalidAccessError, "No render layer can be obtained from the provided element.");
         return 0;
     }
 
-    return layer->isUnclippedDescendant();
+    // We used to compute isUnclippedDescendant only when acceleratedCompositingForOverflowScrollEnabled,
+    // but now we compute it all the time.
+    // FIXME: Remove this if statement and rebaseline the tests that make this assumption.
+    if (!layer->compositor()->acceleratedCompositingForOverflowScrollEnabled())
+        return false;
+
+    return layer->ancestorDependentProperties().isUnclippedDescendant;
 }
 
 String Internals::layerTreeAsText(Document* document, unsigned flags, ExceptionState& exceptionState) const
 {
     if (!document || !document->frame()) {
         exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
         return String();
     }
 
     document->view()->updateLayoutAndStyleForPainting();
@@ skipping 659 matching lines @@
     } else if (type == "none") {
         webtype = blink::ConnectionTypeNone;
     } else {
         exceptionState.throwDOMException(NotFoundError, ExceptionMessages::failedToEnumerate("connection type", type));
         return;
     }
     networkStateNotifier().setWebConnectionTypeForTest(webtype);
 }
 
 } // namespace WebCore