gpu: Add GpuFence framework.

gpu/ipc/service/gpu_channel.h

Index: gpu/ipc/service/gpu_channel.h
diff --git a/gpu/ipc/service/gpu_channel.h b/gpu/ipc/service/gpu_channel.h
index 47c1ba63604df7fe0b6ed6da742fc4575d9acda9..e3dcbb86d71107f8d7a38688025c7a686edeb2dc 100644
--- a/gpu/ipc/service/gpu_channel.h
+++ b/gpu/ipc/service/gpu_channel.h
@@ -27,6 +27,7 @@
 #include "ipc/ipc_sync_channel.h"
 #include "ipc/message_router.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/gpu_fence.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_share_group.h"
 #include "ui/gl/gpu_preference.h"
@@ -37,6 +38,10 @@ namespace base {
 class WaitableEvent;
 }
 
+namespace gl {
+class GLFence;
+}
+
 namespace IPC {
 class MessageFilter;
 }
@@ -150,6 +155,9 @@ class GPU_EXPORT GpuChannel
       uint32_t internalformat,
       SurfaceHandle surface_handle);
 
+  std::unique_ptr<gl::GLFence> CreateFenceForGpuFence(
+      const gfx::GpuFenceHandle& handle);
+
   GpuChannelMessageFilter* filter() const { return filter_.get(); }
 
   // Returns the global order number for the last processed IPC message.