CC Animations: Make LayerAnimationController creation optional

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 ffba9e88c2d8026a8bee7e2f5999da6e8dffc91f..25cbf43c7c08189d0be833c14853f6c0d682a822 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -155,10 +155,13 @@ class LayerTreeTest : public testing::Test, public TestHooks {
     verify_property_trees_ = verify_property_trees;
   }
 
+  const LayerSettings& layer_settings() { return layer_settings_; }
+
  protected:
   LayerTreeTest();
 
   virtual void InitializeSettings(LayerTreeSettings* settings) {}
+  virtual void InitializeLayerSettings(LayerSettings* layer_settings) {}
 
   void RealEndTest();
 
@@ -220,6 +223,8 @@ class LayerTreeTest : public testing::Test, public TestHooks {
 
  private:
   LayerTreeSettings settings_;
+  LayerSettings layer_settings_;
+
   scoped_ptr<LayerTreeHostClientForTesting> client_;
   scoped_ptr<LayerTreeHost> layer_tree_host_;
   FakeOutputSurface* output_surface_;