Create RootWindowTransformer after root window's bounds and scale factor are updated.

ash/test/ash_test_base.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/ash_test_base.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 174 matching lines @@
 
 // static
 bool AshTestBase::SupportsMultipleDisplays() {
 #if defined(OS_WIN)
   return base::win::GetVersion() < base::win::VERSION_WIN8;
 #else
   return true;
 #endif
 }
 
+// static
+bool AshTestBase::SupportsHostWindowResize() {
+#if defined(OS_WIN)
+  return base::win::GetVersion() < base::win::VERSION_WIN8;
+#else
+  return true;
+#endif
+}
+
 void AshTestBase::UpdateDisplay(const std::string& display_specs) {
   DisplayManagerTestApi display_manager_test_api(
       Shell::GetInstance()->display_manager());
   display_manager_test_api.UpdateDisplay(display_specs);
 }
 
 aura::RootWindow* AshTestBase::CurrentContext() {
   return ash_test_helper_->CurrentContext();
 }
 
@@ skipping 70 matching lines @@
       SetHasActiveUser(user_logged_in);
 }
 
 void AshTestBase::SetCanLockScreen(bool can_lock_screen) {
   ash_test_helper_->test_shell_delegate()->test_session_state_delegate()->
       SetCanLockScreen(can_lock_screen);
 }
 
 }  // namespace test
 }  // namespace ash