Remove WebKit::Platform dependencies from cc

cc/layer_tree_host_impl.cc

 // Copyright 2011 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 "config.h"
 
 #include "cc/layer_tree_host_impl.h"
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
@@ skipping 151 matching lines @@
         return make_scoped_ptr(new LayerTreeHostImplTimeSourceAdapter(layerTreeHostImpl, timeSource));
     }
     virtual ~LayerTreeHostImplTimeSourceAdapter()
     {
         m_timeSource->setClient(0);
         m_timeSource->setActive(false);
     }
 
     virtual void onTimerTick() OVERRIDE
     {
-        // FIXME: We require that animate be called on the impl thread. This
-        // avoids asserts in single threaded mode. Ideally background ticking
-        // would be handled by the proxy/scheduler and this could be removed.
-        DebugScopedSetImplThread impl;
-
         m_layerTreeHostImpl->animate(base::TimeTicks::Now(), base::Time::Now());
     }
 
     void setActive(bool active)
     {
         if (active != m_timeSource->active())
             m_timeSource->setActive(active);
     }
 
 private:
@@ skipping 1302 matching lines @@
     ScrollbarAnimationController* scrollbarController = layer->scrollbarAnimationController();
     double monotonicTime = (time - base::TimeTicks()).InSecondsF();
     if (scrollbarController && scrollbarController->animate(monotonicTime))
         m_client->setNeedsRedrawOnImplThread();
 
     for (size_t i = 0; i < layer->children().size(); ++i)
         animateScrollbarsRecursive(layer->children()[i], time);
 }
 
 }  // namespace cc