Use a lock to deal with concurrent access to the m_evictedBackings

cc/thread_proxy.h

 // 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.
 
 #ifndef CC_THREAD_PROXY_H_
 #define CC_THREAD_PROXY_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "cc/animation_events.h"
@@ skipping 70 matching lines @@
 private:
     ThreadProxy(LayerTreeHost*, scoped_ptr<Thread> implThread);
 
     struct BeginFrameAndCommitState {
         BeginFrameAndCommitState();
         ~BeginFrameAndCommitState();
 
         base::TimeTicks monotonicFrameBeginTime;
         scoped_ptr<ScrollAndScaleSet> scrollInfo;
         gfx::Transform implTransform;
-        PrioritizedResourceManager::BackingList evictedContentsTexturesBackings;
         size_t memoryAllocationLimitBytes;
     };
 
     // Called on main thread
     void beginFrame(scoped_ptr<BeginFrameAndCommitState> beginFrameState);
     void didCommitAndDrawFrame();
     void didCompleteSwapBuffers();
     void setAnimationEvents(scoped_ptr<AnimationEventsVector>, base::Time wallClockTime);
     void beginContextRecreation();
     void tryToRecreateContext();
@@ skipping 73 matching lines @@
     base::TimeDelta m_totalCommitTime;
     size_t m_totalCommitCount;
 
     bool m_deferCommits;
     scoped_ptr<BeginFrameAndCommitState> m_pendingDeferredCommit;
 };
 
 }  // namespace cc
 
 #endif  // CC_THREAD_PROXY_H_