Parameterize TaskRunner used by ui::Compositor

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 79bf691c41520057728284ab3f1d4ba9f165fc77..a10b62fcedfafd99b2c31256eafb6dfab46586ee 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -11,6 +11,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
+#include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
@@ -131,7 +132,8 @@ class COMPOSITOR_EXPORT Compositor
       NON_EXPORTED_BASE(public LayerAnimatorCollectionDelegate) {
  public:
   Compositor(gfx::AcceleratedWidget widget,
-             ui::ContextFactory* context_factory);
+             ui::ContextFactory* context_factory,
+             scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   virtual ~Compositor();
 
   ui::ContextFactory* context_factory() { return context_factory_; }
@@ -274,6 +276,7 @@ class COMPOSITOR_EXPORT Compositor
   scoped_refptr<cc::Layer> root_web_layer_;
   scoped_ptr<cc::LayerTreeHost> host_;
   scoped_refptr<base::MessageLoopProxy> compositor_thread_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // The manager of vsync parameters for this compositor.
   scoped_refptr<CompositorVSyncManager> vsync_manager_;