cc: Remove the capability to give up and leave compositing mode.

cc/layers/tiled_layer_unittest.cc

Index: cc/layers/tiled_layer_unittest.cc
diff --git a/cc/layers/tiled_layer_unittest.cc b/cc/layers/tiled_layer_unittest.cc
index a0c469fe64a6f74bb1d948baa3fa12477f5a1085..35450b95e61dd1de86de9876969ac4fa94672e9e 100644
--- a/cc/layers/tiled_layer_unittest.cc
+++ b/cc/layers/tiled_layer_unittest.cc
@@ -68,13 +68,11 @@ class SynchronousOutputSurfaceLayerTreeHost : public LayerTreeHost {
     return output_surface_created_;
   }
 
-  virtual CreateResult OnCreateAndInitializeOutputSurfaceAttempted(
+  virtual void OnCreateAndInitializeOutputSurfaceAttempted(
       bool success) OVERRIDE {
-    CreateResult result =
-        LayerTreeHost::OnCreateAndInitializeOutputSurfaceAttempted(success);
+    LayerTreeHost::OnCreateAndInitializeOutputSurfaceAttempted(success);
     output_surface_created_ = success;
     run_loop_.Quit();
-    return result;
   }
 
  private: