views/mus: Install a mus-friend ContextFactory for tests.

ui/views/test/platform_test_helper.cc

 // Copyright 2016 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 "ui/views/test/platform_test_helper.h"
 
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "ui/compositor/test/context_factories_for_test.h"
 #include "ui/views/widget/widget.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/window.h"
 #endif
 
 namespace views {
 namespace {
 
 PlatformTestHelper::Factory test_helper_factory;
 bool is_mus = false;
 
 }  // namespace
 
+PlatformTestHelper::~PlatformTestHelper() {
+  ui::TerminateContextFactoryForTests();
+}
+
 void PlatformTestHelper::set_factory(const Factory& factory) {
   DCHECK(test_helper_factory.is_null());
   test_helper_factory = factory;
 }
 
 // static
 std::unique_ptr<PlatformTestHelper> PlatformTestHelper::Create() {
   return !test_helper_factory.is_null()
              ? test_helper_factory.Run()
              : base::WrapUnique(new PlatformTestHelper);
 }
 
 // static
 void PlatformTestHelper::SetIsMus() {
   is_mus = true;
 }
 
 // static
 bool PlatformTestHelper::IsMus() {
   return is_mus;
 }
 
 #if defined(USE_AURA)
 void PlatformTestHelper::SimulateNativeDestroy(Widget* widget) {
   delete widget->GetNativeView();
 }
 #endif
 
+void PlatformTestHelper::InitializeContextFactory(
+    ui::ContextFactory** context_factory,
+    ui::ContextFactoryPrivate** context_factory_private) {
+  bool enable_pixel_output = false;
+  ui::InitializeContextFactoryForTests(enable_pixel_output, context_factory,
+                                       context_factory_private);
+}
+
 }  // namespace views