gpu: Add GpuFence framework.

gpu/ipc/client/gpu_fence_impl.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef GPU_IPC_CLIENT_GPU_FENCE_IMPL_H_
+#define GPU_IPC_CLIENT_GPU_FENCE_IMPL_H_
+
+#include "gpu/gpu_export.h"
+#include "ui/gfx/gpu_fence.h"
+#include "ui/gfx/shared_event.h"
+
+namespace gpu {
+
+// Provides common implementation of a GPU fence.
+class GPU_EXPORT GpuFenceImpl : public gfx::GpuFence {
+ public:
+  GpuFenceImpl();
+  explicit GpuFenceImpl(const gfx::GpuFenceHandle& handle);
+  ~GpuFenceImpl() override;
+
+  static gfx::GpuFenceHandle CreateForChildProcess(
+      base::ProcessHandle child_process);
+
+  // Type-checking upcast routine. Returns an NULL on failure.
+  static GpuFenceImpl* FromClientFence(ClientFence fence);
+
+  // Overridden from gfx::GpuFence:
+  bool IsSignaled() override;
+  bool Wait(const base::TimeDelta& max_time) override;
+  void Reset() override;
+  gfx::GpuFenceHandle GetHandle() const override;
+  ClientFence AsClientFence() override;
+
+ private:
+  gfx::SharedEvent shared_event_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuFenceImpl);
+};
+
+}  // namespace gpu
+
+#endif  // GPU_IPC_CLIENT_GPU_FENCE_IMPL_H_