aura: Make sure TestScreen objects are destroyed properly.

ui/views_content_client/views_content_client_main_parts_chromeos.cc

 // Copyright 2014 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 "content/public/browser/context_factory.h"
 #include "content/shell/browser/shell_browser_context.h"
 #include "ui/aura/test/test_screen.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/screen.h"
 #include "ui/views_content_client/views_content_client.h"
@@ skipping 29 matching lines @@
       const content::MainFunctionParams& content_params,
       ViewsContentClient* views_content_client);
   virtual ~ViewsContentClientMainPartsChromeOS() {}
 
   // content::BrowserMainParts:
   virtual void PreMainMessageLoopRun() OVERRIDE;
   virtual void PostMainMessageLoopRun() OVERRIDE;
 
  private:
   // Enable a minimal set of views::corewm to be initialized.
+  scoped_ptr<gfx::Screen> test_screen_;
   scoped_ptr< ::wm::WMTestHelper> wm_test_helper_;
   scoped_ptr< ::wm::NestedAcceleratorController> nested_accelerator_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(ViewsContentClientMainPartsChromeOS);
 };
 
 ViewsContentClientMainPartsChromeOS::ViewsContentClientMainPartsChromeOS(
     const content::MainFunctionParams& content_params,
     ViewsContentClient* views_content_client)
     : ViewsContentClientMainPartsAura(content_params, views_content_client) {
 }
 
 void ViewsContentClientMainPartsChromeOS::PreMainMessageLoopRun() {
   ViewsContentClientMainPartsAura::PreMainMessageLoopRun();
 
   gfx::Size host_size(800, 600);
-  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE,
-                                 aura::TestScreen::Create(host_size));
+  test_screen_.reset(aura::TestScreen::Create(host_size));
+  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, test_screen_.get());
   // Set up basic pieces of views::corewm.
   wm_test_helper_.reset(
       new ::wm::WMTestHelper(host_size, content::GetContextFactory()));
   // Ensure the X window gets mapped.
   wm_test_helper_->host()->Show();
 
   // Ensure Aura knows where to open new windows.
   aura::Window* root_window = wm_test_helper_->host()->window();
   views_content_client()->task().Run(browser_context(), root_window);
 
   nested_accelerator_controller_.reset(
       new ::wm::NestedAcceleratorController(new NestedAcceleratorDelegate));
   aura::client::SetDispatcherClient(root_window,
                                     nested_accelerator_controller_.get());
 }
 
 void ViewsContentClientMainPartsChromeOS::PostMainMessageLoopRun() {
   aura::client::SetDispatcherClient(wm_test_helper_->host()->window(), NULL);
   nested_accelerator_controller_.reset();
   wm_test_helper_.reset();
+  test_screen_.reset();
 
   ViewsContentClientMainPartsAura::PostMainMessageLoopRun();
 }
 
 }  // namespace
 
 // static
 ViewsContentClientMainParts* ViewsContentClientMainParts::Create(
     const content::MainFunctionParams& content_params,
     ViewsContentClient* views_content_client) {
   return new ViewsContentClientMainPartsChromeOS(
       content_params, views_content_client);
 }
 
 }  // namespace ui