gpu: Add GpuFence framework.

gpu/ipc/service/gpu_channel.cc

Index: gpu/ipc/service/gpu_channel.cc
diff --git a/gpu/ipc/service/gpu_channel.cc b/gpu/ipc/service/gpu_channel.cc
index 8ed788a38174e3cf06d81a61d7c6181fe5a81986..46981e6c1c71b080b9ad3f3afb95151a7ccb6adb 100644
--- a/gpu/ipc/service/gpu_channel.cc
+++ b/gpu/ipc/service/gpu_channel.cc
@@ -42,6 +42,8 @@
 #include "ipc/ipc_channel.h"
 #include "ipc/message_filter.h"
 #include "ui/gl/gl_context.h"
+#include "ui/gl/gl_fence.h"
+#include "ui/gl/gl_fence_shared_event.h"
 #include "ui/gl/gl_image_shared_memory.h"
 #include "ui/gl/gl_surface.h"
 
@@ -1063,4 +1065,9 @@ scoped_refptr<gl::GLImage> GpuChannel::CreateImageForGpuMemoryBuffer(
   }
 }
 
+std::unique_ptr<gl::GLFence> GpuChannel::CreateFenceForGpuFence(
+    const gfx::GpuFenceHandle& handle) {
+  return base::MakeUnique<gl::GLFenceSharedEvent>(handle.shared_event_handle);
+}
+
 }  // namespace gpu