gpu: Add GpuFence framework.

gpu/command_buffer/client/gpu_memory_buffer_manager.h

Index: gpu/command_buffer/client/gpu_memory_buffer_manager.h
diff --git a/gpu/command_buffer/client/gpu_memory_buffer_manager.h b/gpu/command_buffer/client/gpu_memory_buffer_manager.h
index 921b42e8e34ff6fa2dde9e4593e80e6ff133e5bc..a598efe79bdcb261f31b175bd7f9f3dfeaecfd1f 100644
--- a/gpu/command_buffer/client/gpu_memory_buffer_manager.h
+++ b/gpu/command_buffer/client/gpu_memory_buffer_manager.h
@@ -10,6 +10,7 @@
 #include "gpu/gpu_export.h"
 #include "gpu/ipc/common/surface_handle.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/gpu_fence.h"
 #include "ui/gfx/gpu_memory_buffer.h"
 
 namespace gpu {
@@ -37,6 +38,16 @@ class GPU_EXPORT GpuMemoryBufferManager {
   virtual void SetDestructionSyncToken(gfx::GpuMemoryBuffer* buffer,
                                        const gpu::SyncToken& sync_token) = 0;
 
+  // Creates a GpuFence that can be shared with another process.
+  virtual std::unique_ptr<gfx::GpuFence> CreateGpuFence() = 0;
+
+  // Creates a GpuFence from existing handle.
+  virtual std::unique_ptr<gfx::GpuFence> CreateGpuFenceFromHandle(
+      const gfx::GpuFenceHandle& handle) = 0;
+
+  // Returns a GpuFence instance given a ClientFence. Returns NULL on failure.
+  virtual gfx::GpuFence* GpuFenceFromClientFence(ClientFence fence) = 0;
+
  protected:
   virtual ~GpuMemoryBufferManager();
 };