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

mash/test/mash_test_suite.h

 // 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.
 
 #ifndef MASH_TEST_TEST_SUITE_H_
 #define MASH_TEST_TEST_SUITE_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/test/test_discardable_memory_allocator.h"
 #include "base/test/test_suite.h"
 
 namespace aura {
 class Env;
 }
 
+namespace ui {
+class FakeContextFactory;
+}
+
 namespace mash {
 namespace test {
 
-class TestContextFactory;
-
 class MashTestSuite : public base::TestSuite {
  public:
   MashTestSuite(int argc, char** argv);
   ~MashTestSuite() override;
 
  protected:
   // base::TestSuite:
   void Initialize() override;
   void Shutdown() override;
 
  private:
   base::TestDiscardableMemoryAllocator discardable_memory_allocator_;
   std::unique_ptr<aura::Env> env_;
-  std::unique_ptr<TestContextFactory> compositor_context_factory_;
+  std::unique_ptr<ui::FakeContextFactory> context_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MashTestSuite);
 };
 
 }  // namespace test
 }  // namespace mash
 
 #endif  // MASH_TEST_TEST_SUITE_H_