cc: Split ThreadProxy into ProxyMain and ProxyImpl

cc/test/layer_tree_test.h

Index: cc/test/layer_tree_test.h
diff --git a/cc/test/layer_tree_test.h b/cc/test/layer_tree_test.h
index ba4e7ae03164592aca976654dcee6825a2f1003c..3a5ffdfe10613c6e12fcafd87e9665627d1fb089 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -22,6 +22,8 @@ class LayerImpl;
 class LayerTreeHost;
 class LayerTreeHostClient;
 class LayerTreeHostImpl;
+class ProxyMain;
+class ProxyImpl;
 class TestContextProvider;
 class TestGpuMemoryBufferManager;
 class TestWebGraphicsContext3D;
@@ -140,8 +142,6 @@ class TestHooks : public AnimationDelegate {
   virtual void ReleaseOutputSurfaceOnImpl() {}
   virtual void FinishGLOnImpl() {}
   virtual void StartCommitOnImpl() {}
-  virtual void InitializeImplOnImpl() {}
-  virtual void WillCloseLayerTreeHostOnImpl() {}
 
   // Hooks for ProxyMain
   virtual void ReceivedDidCompleteSwapBuffers() {}
@@ -250,9 +250,10 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   virtual void BeginTest() = 0;
   virtual void SetupTree();
 
+  // TODO(khushalsagar): Add mode for running remote channel tests.
   virtual void RunTest(bool threaded, bool delegating_renderer);
 
-  bool HasImplThread() { return !!impl_thread_; }
+  bool HasImplThread() const { return !!impl_thread_; }
   base::SingleThreadTaskRunner* ImplThreadTaskRunner() {
     DCHECK(task_runner_provider());
     base::SingleThreadTaskRunner* impl_thread_task_runner =
@@ -281,6 +282,12 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   FakeOutputSurface* output_surface() { return output_surface_; }
   int LastCommittedSourceFrameNumber(LayerTreeHostImpl* impl) const;
 
+  // Use these only for ProxyMain tests in threaded mode.
+  // TODO(khushalsagar): Update these when adding support for remote channel
+  // tests.
+  ProxyMain* GetProxyMain() const;
+  ProxyImpl* GetProxyImpl() const;
+
   void DestroyLayerTreeHost();
 
   // By default, output surface recreation is synchronous.