Composited Animations: Support --disable-threaded-animation in new animation system.

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 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 76 matching lines @@
 }
 
 ScrollingCoordinator::ScrollingCoordinator(Page* page)
     : m_page(page)
     , m_scrollGestureRegionIsDirty(false)
     , m_touchEventTargetRectsAreDirty(false)
     , m_shouldScrollOnMainThreadDirty(false)
     , m_wasFrameScrollable(false)
     , m_lastMainThreadScrollingReasons(0)
 {
-    if (RuntimeEnabledFeatures::compositorAnimationTimelinesEnabled()) {
+    if (RuntimeEnabledFeatures::compositorAnimationTimelinesEnabled() && Platform::current()->isThreadedAnimationEnabled()) {
         ASSERT(m_page);
         ASSERT(m_page->mainFrame()->isLocalFrame());
         ASSERT(Platform::current()->compositorSupport());
         m_programmaticScrollAnimatorTimeline = adoptPtr(Platform::current()->compositorSupport()->createAnimationTimeline());
         m_page->chromeClient().attachCompositorAnimationTimeline(m_programmaticScrollAnimatorTimeline.get(), toLocalFrame(m_page->mainFrame()));
     }
 }
 
 ScrollingCoordinator::~ScrollingCoordinator()
 {
@@ skipping 968 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : nullptr)
         return WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace blink