gpu: Add GpuFence framework.

gpu/ipc/client/gpu_channel_host.cc

Index: gpu/ipc/client/gpu_channel_host.cc
diff --git a/gpu/ipc/client/gpu_channel_host.cc b/gpu/ipc/client/gpu_channel_host.cc
index b639d8ffa54f83f61e2adb13312e1fef91feffd3..c44cd9ac61b3439a19bd111af9d935aca73002a7 100644
--- a/gpu/ipc/client/gpu_channel_host.cc
+++ b/gpu/ipc/client/gpu_channel_host.cc
@@ -69,6 +69,7 @@ GpuChannelHost::GpuChannelHost(
       gpu_info_(gpu_info),
       gpu_memory_buffer_manager_(gpu_memory_buffer_manager) {
   next_image_id_.GetNext();
+  next_fence_id_.GetNext();
   next_route_id_.GetNext();
   next_stream_id_.GetNext();
 }
@@ -282,6 +283,18 @@ int32_t GpuChannelHost::ReserveImageId() {
   return next_image_id_.GetNext();
 }
 
+gfx::GpuFenceHandle GpuChannelHost::ShareGpuFenceToGpuProcess(
+    const gfx::GpuFenceHandle& source_handle) {
+  gfx::GpuFenceHandle handle;
+  handle.shared_event_handle =
+      gfx::SharedEvent::DuplicateHandle(source_handle.shared_event_handle);

[ericrk, 2017/03/10 03:04:39]

We don't need to call ShareToProcess here? Just duplicate?

[reveman, 2017/03/13 12:33:05]

This looks the same as GpuChannelHost::ShareToGpuProcess. We need the same logic
as all other shmem so it this doesn't match then it needs to be updated.

+  return handle;
+}
+
+int32_t GpuChannelHost::ReserveFenceId() {
+  return next_fence_id_.GetNext();
+}
+
 int32_t GpuChannelHost::GenerateRouteID() {
   return next_route_id_.GetNext();
 }