Use WebKit compositor in ui::Layer

ui/aura_shell/test_suite.cc

Index: ui/aura_shell/test_suite.cc
diff --git a/ui/aura_shell/test_suite.cc b/ui/aura_shell/test_suite.cc
index 2652a24b93cecfb5eb95cc1c04867c7443285c7d..5ccb18ffba78e7fc8150887cfb38ed529a98a0ef 100644
--- a/ui/aura_shell/test_suite.cc
+++ b/ui/aura_shell/test_suite.cc
@@ -9,6 +9,7 @@
 #include "build/build_config.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
+#include "ui/gfx/compositor/compositor_test_support.h"
 #include "ui/gfx/gfx_paths.h"
 #include "ui/gfx/gl/gl_implementation.h"
 
@@ -27,9 +28,11 @@ void AuraShellTestSuite::Initialize() {
   // Force unittests to run using en-US so if we test against string
   // output, it'll pass regardless of the system language.
   ui::ResourceBundle::InitSharedInstance("en-US");
+  ui::CompositorTestSupport::Initialize();
 }
 
 void AuraShellTestSuite::Shutdown() {
+  ui::CompositorTestSupport::Terminate();
   ui::ResourceBundle::CleanupSharedInstance();
 
   base::TestSuite::Shutdown();