cc: Remove cc::Thread and cc::ThreadImpl.

cc/trees/thread_proxy.h

Index: cc/trees/thread_proxy.h
diff --git a/cc/trees/thread_proxy.h b/cc/trees/thread_proxy.h
index 7a6924233a415213a2ea4d010f6c944c0dfef3c1..9f3f457fada4c12e226dd808db9436111f42a033 100644
--- a/cc/trees/thread_proxy.h
+++ b/cc/trees/thread_proxy.h
@@ -17,6 +17,8 @@
 #include "cc/trees/layer_tree_host_impl.h"
 #include "cc/trees/proxy.h"
 
+namespace base { class SingleThreadTaskRunner; }
+
 namespace cc {
 
 class ContextProvider;
@@ -25,7 +27,6 @@ class LayerTreeHost;
 class ResourceUpdateQueue;
 class Scheduler;
 class ScopedThreadProxy;
-class Thread;
 
 class ThreadProxy : public Proxy,
                     LayerTreeHostImplClient,
@@ -33,8 +34,9 @@ class ThreadProxy : public Proxy,
                     ResourceUpdateControllerClient,
                     VSyncProvider {
  public:
-  static scoped_ptr<Proxy> Create(LayerTreeHost* layer_tree_host,
-                                  scoped_ptr<Thread> impl_thread);
+  static scoped_ptr<Proxy> Create(
+      LayerTreeHost* layer_tree_host,
+      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
 
   virtual ~ThreadProxy();
 
@@ -120,7 +122,8 @@ class ThreadProxy : public Proxy,
   }
 
  private:
-  ThreadProxy(LayerTreeHost* layer_tree_host, scoped_ptr<Thread> impl_thread);
+  ThreadProxy(LayerTreeHost* layer_tree_host,
+              scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
 
   struct BeginFrameAndCommitState {
     BeginFrameAndCommitState();