Make cc::Display not own its BeginFrameSource

ui/compositor/test/in_process_context_factory.h

 // 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.
 
 #ifndef UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_FACTORY_H_
 #define UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_FACTORY_H_
 
 #include <stdint.h>
 #include <memory>
 
@@ skipping 71 matching lines @@
   cc::TestSharedBitmapManager shared_bitmap_manager_;
   cc::TestGpuMemoryBufferManager gpu_memory_buffer_manager_;
   cc::TestImageFactory image_factory_;
   cc::TestTaskGraphRunner task_graph_runner_;
   uint32_t next_surface_client_id_;
   bool use_test_surface_;
   bool context_factory_for_test_;
   cc::SurfaceManager* surface_manager_;
   base::ObserverList<ContextFactoryObserver> observer_list_;
 
-  base::hash_map<Compositor*, std::unique_ptr<cc::Display>>
+  struct PerCompositorData;
+  base::hash_map<Compositor*, std::unique_ptr<PerCompositorData>>
       per_compositor_data_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessContextFactory);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_FACTORY_H_