cc: Make separate interface for BeginFrame ipc from OutputSurface

cc/trees/layer_tree_host_unittest_no_message_loop.cc

Index: cc/trees/layer_tree_host_unittest_no_message_loop.cc
diff --git a/cc/trees/layer_tree_host_unittest_no_message_loop.cc b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
index fb0e2be225ffecdee4f70e0ff6ebf61fb55a5b50..e645e93734cdc071ebdae4faa013a066da9e52fd 100644
--- a/cc/trees/layer_tree_host_unittest_no_message_loop.cc
+++ b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
@@ -13,6 +13,7 @@
 #include "cc/output/output_surface.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/resources/resource_provider.h"
+#include "cc/scheduler/begin_frame_source.h"
 #include "cc/test/fake_delegated_renderer_layer.h"
 #include "cc/test/test_context_provider.h"
 #include "cc/trees/layer_tree_host.h"
@@ -100,8 +101,13 @@ class LayerTreeHostNoMessageLoopTest
   void SetupLayerTreeHost() {
     LayerTreeSettings settings;
     settings.single_thread_proxy_scheduler = false;
-    layer_tree_host_ =
-        LayerTreeHost::CreateSingleThreaded(this, this, NULL, settings, NULL);
+    layer_tree_host_ = LayerTreeHost::CreateSingleThreaded(
+                           this,
+                           this,
+                           NULL,
+                           settings,
+                           NULL,
+                           scoped_ptr<ExternalBeginFrameSource>());
     layer_tree_host_->SetViewportSize(size_);
     layer_tree_host_->SetRootLayer(root_layer_);
   }