aura: Clean up compositor initialization/destruction.

ash/test/test_shell_delegate.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/test/test_shell_delegate.h"
 
 #include <limits>
 
 #include "ash/caps_lock_delegate_stub.h"
 #include "ash/host/root_window_host_factory.h"
 #include "ash/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/test_launcher_delegate.h"
 #include "ash/test/test_session_state_delegate.h"
 #include "ash/wm/window_util.h"
 #include "base/logging.h"
 #include "content/public/test/test_browser_context.h"
 #include "ui/aura/window.h"
+#include "ui/compositor/compositor.h"
 
 namespace ash {
 namespace test {
 
 TestShellDelegate::TestShellDelegate()
     : spoken_feedback_enabled_(false),
       high_contrast_enabled_(false),
       screen_magnifier_enabled_(false),
       screen_magnifier_type_(kDefaultMagnifierType),
       large_cursor_enabled_(false),
@@ skipping 176 matching lines @@
 
 ui::MenuModel* TestShellDelegate::CreateContextMenu(aura::RootWindow* root) {
   return NULL;
 }
 
 double TestShellDelegate::GetSavedScreenMagnifierScale() {
   return std::numeric_limits<double>::min();
 }
 
 RootWindowHostFactory* TestShellDelegate::CreateRootWindowHostFactory() {
+  // The ContextFactory must exist before any Compositors are created.
+  bool allow_test_contexts = true;
+  ui::Compositor::InitializeContextFactoryForTests(allow_test_contexts);
+
   return RootWindowHostFactory::Create();
 }
 
 base::string16 TestShellDelegate::GetProductName() const {
   return base::string16();
 }
 
 TestSessionStateDelegate* TestShellDelegate::test_session_state_delegate() {
   return test_session_state_delegate_;
 }
 
 }  // namespace test
 }  // namespace ash