Attempt 2 at : Makes tests either use mock compositor or mock

ui/gfx/compositor/compositor_cc.h

Index: ui/gfx/compositor/compositor_cc.h
diff --git a/ui/gfx/compositor/compositor_cc.h b/ui/gfx/compositor/compositor_cc.h
index def218110e0aabfcbba7349b2723bd2aa0888351..3216f9e3630ef34ae56df800de0a5b1cb3849905 100644
--- a/ui/gfx/compositor/compositor_cc.h
+++ b/ui/gfx/compositor/compositor_cc.h
@@ -90,10 +90,6 @@ class COMPOSITOR_EXPORT CompositorCC
   static void Initialize(bool useThread);
   static void Terminate();
 
-  // If necessary enables the test context. If the test context is enabled the
-  // compositor does not render anything to screen.
-  static void EnableTestContextIfNecessary();
-
  protected:
   // Compositor implementation.
   virtual Texture* CreateTexture() OVERRIDE;
@@ -123,9 +119,6 @@ class COMPOSITOR_EXPORT CompositorCC
   WebKit::WebLayer root_web_layer_;
   WebKit::WebLayerTreeView host_;
 
-  // See description above SetTestContextEnabled.
-  static bool test_context_enabled_;
-
   DISALLOW_COPY_AND_ASSIGN(CompositorCC);
 };