gpu: Add GpuFence framework.

gpu/ipc/client/command_buffer_proxy_impl.cc

Index: gpu/ipc/client/command_buffer_proxy_impl.cc
diff --git a/gpu/ipc/client/command_buffer_proxy_impl.cc b/gpu/ipc/client/command_buffer_proxy_impl.cc
index 07c31ff9a951eb93f66c7133586559ffc5fe65a4..88be6e52458adb8f87cf0ca8971ba9d263ec170e 100644
--- a/gpu/ipc/client/command_buffer_proxy_impl.cc
+++ b/gpu/ipc/client/command_buffer_proxy_impl.cc
@@ -664,6 +664,42 @@ void CommandBufferProxyImpl::SignalQuery(uint32_t query,
   signal_tasks_.insert(std::make_pair(signal_id, callback));
 }
 
+int32_t CommandBufferProxyImpl::CreateFence(ClientFence fence) {
+  CheckLock();
+  if (last_state_.error != gpu::error::kNoError)
+    return -1;
+
+  int32_t new_id = channel_->ReserveFenceId();
+
+  gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager =
+      channel_->gpu_memory_buffer_manager();
+  gfx::GpuFence* gpu_fence =
+      gpu_memory_buffer_manager->GpuFenceFromClientFence(fence);
+  DCHECK(gpu_fence);
+
+  // This handle is owned by the GPU process and must be passed to it or it
+  // will leak. In otherwords, do not early out on error between here and the
+  // sending of the CreateFence IPC below.
+  gfx::GpuFenceHandle handle =
+      channel_->ShareGpuFenceToGpuProcess(gpu_fence->GetHandle());
+
+  GpuCommandBufferMsg_CreateFence_Params params;
+  params.id = new_id;
+  params.gpu_fence = handle;
+
+  Send(new GpuCommandBufferMsg_CreateFence(route_id_, params));
+
+  return new_id;
+}
+
+void CommandBufferProxyImpl::DestroyFence(int32_t id) {
+  CheckLock();
+  if (last_state_.error != gpu::error::kNoError)
+    return;
+
+  Send(new GpuCommandBufferMsg_DestroyFence(route_id_, id));
+}
+
 void CommandBufferProxyImpl::TakeFrontBuffer(const gpu::Mailbox& mailbox) {
   CheckLock();
   if (last_state_.error != gpu::error::kNoError)