Merge AcceleratedCompositingForOverflowScroll into PreferCompositingToLCDText.

Source/core/rendering/compositing/CompositingRequirementsUpdater.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google 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
@@ skipping 210 matching lines @@
         directReasons |= CompositingReasonVideoOverlay;
 
     if (compositor->canBeComposited(layer))
         reasonsToComposite |= directReasons;
 
     // Next, accumulate reasons related to overlap.
     // If overlap testing is used, this reason will be overridden. If overlap testing is not
     // used, we must assume we overlap if there is anything composited behind us in paint-order.
     CompositingReasons overlapCompositingReason = currentRecursionData.m_subtreeIsCompositing ? CompositingReasonAssumedOverlap : CompositingReasonNone;
 
-    if (m_renderView.compositor()->acceleratedCompositingForOverflowScrollEnabled()) {
+    if (m_renderView.compositor()->preferCompositingToLCDTextEnabled()) {
         Vector<size_t> unclippedDescendantsToRemove;
         for (size_t i = 0; i < unclippedDescendants.size(); i++) {
             RenderLayer* unclippedDescendant = unclippedDescendants.at(i);
             // If we've reached the containing block of one of the unclipped
             // descendants, that element is no longer relevant to whether or not we
             // should opt in. Unfortunately we can't easily remove from the list
             // while we're iterating, so we have to store it for later removal.
             if (unclippedDescendant->renderer()->containingBlock() == layer->renderer()) {
                 unclippedDescendantsToRemove.append(i);
                 continue;
@@ skipping 170 matching lines @@
 
         descendantHas3DTransform |= anyDescendantHas3DTransform || layer->has3DTransform();
     }
 
     // At this point we have finished collecting all reasons to composite this layer.
     layer->setCompositingReasons(reasonsToComposite);
 
 }
 
 } // namespace blink