gpu: Add GpuFence framework.

content/browser/gpu/browser_gpu_memory_buffer_manager.h

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.h
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.h b/content/browser/gpu/browser_gpu_memory_buffer_manager.h
index 0d526d703b4dd5603fc9aa4632c1a98519bd9049..d19e21afa9072fd15f48d57541009766520cbbec 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.h
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.h
@@ -51,6 +51,8 @@ class CONTENT_EXPORT BrowserGpuMemoryBufferManager
   using CreateCallback =
       base::Callback<void(const gfx::GpuMemoryBufferHandle& handle)>;
   using AllocationCallback = CreateCallback;
+  using FenceCreationCallback =
+      base::Callback<void(const gfx::GpuFenceHandle& handle)>;
 
   BrowserGpuMemoryBufferManager(int gpu_client_id,
                                 uint64_t gpu_client_tracing_id);
@@ -75,6 +77,10 @@ class CONTENT_EXPORT BrowserGpuMemoryBufferManager
       gfx::BufferFormat format) override;
   void SetDestructionSyncToken(gfx::GpuMemoryBuffer* buffer,
                                const gpu::SyncToken& sync_token) override;
+  std::unique_ptr<gfx::GpuFence> CreateGpuFence() override;
+  std::unique_ptr<gfx::GpuFence> CreateGpuFenceFromHandle(
+      const gfx::GpuFenceHandle& handle) override;
+  gfx::GpuFence* GpuFenceFromClientFence(ClientFence fence) override;
 
   // Overridden from base::trace_event::MemoryDumpProvider:
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
@@ -93,6 +99,8 @@ class CONTENT_EXPORT BrowserGpuMemoryBufferManager
       base::ProcessHandle child_process_handle,
       int child_client_id,
       const gpu::SyncToken& sync_token);
+  void CreateGpuFenceForChildProcess(base::ProcessHandle child_process_handle,
+                                     const FenceCreationCallback& callback);
   void ProcessRemoved(base::ProcessHandle process_handle, int client_id);
 
   bool IsNativeGpuMemoryBufferConfiguration(gfx::BufferFormat format,