Centralize FrameSinkId allocation in one place

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>
 
 #include "base/macros.h"
 #include "cc/surfaces/display.h"
+#include "cc/surfaces/frame_sink_id_allocator.h"
 #include "cc/test/test_gpu_memory_buffer_manager.h"
 #include "cc/test/test_image_factory.h"
 #include "cc/test/test_shared_bitmap_manager.h"
 #include "cc/test/test_task_graph_runner.h"
 #include "gpu/ipc/common/surface_handle.h"
 #include "ui/compositor/compositor.h"
 
 namespace cc {
 class SurfaceManager;
 }
@@ skipping 54 matching lines @@
   struct PerCompositorData;
 
   PerCompositorData* CreatePerCompositorData(ui::Compositor* compositor);
 
   scoped_refptr<InProcessContextProvider> shared_main_thread_contexts_;
   scoped_refptr<InProcessContextProvider> shared_worker_context_provider_;
   cc::TestSharedBitmapManager shared_bitmap_manager_;
   cc::TestGpuMemoryBufferManager gpu_memory_buffer_manager_;
   cc::TestImageFactory image_factory_;
   cc::TestTaskGraphRunner task_graph_runner_;
-  uint32_t next_surface_sink_id_;
+  cc::FrameSinkIdAllocator frame_sink_id_allocator_;
   bool use_test_surface_;
   bool context_factory_for_test_;
   cc::SurfaceManager* surface_manager_;
   base::ObserverList<ContextFactoryObserver> observer_list_;
 
   using PerCompositorDataMap =
       base::hash_map<ui::Compositor*, std::unique_ptr<PerCompositorData>>;
   PerCompositorDataMap per_compositor_data_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessContextFactory);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_FACTORY_H_