Switch DRM platform to using a separate thread

ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h

Index: ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h
diff --git a/ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h b/ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h
new file mode 100644
index 0000000000000000000000000000000000000000..d0ed286dae6c4b9e25dfb4a9b347826cf9428f61
--- /dev/null
+++ b/ui/ozone/platform/drm/gpu/drm_gpu_platform_support_proxy.h
@@ -0,0 +1,42 @@
+// Copyright 2015 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 UI_OZONE_PLATFORM_DRM_GPU_DRM_GPU_PLATFORM_SUPPORT_PROXY_H_
+#define UI_OZONE_PLATFORM_DRM_GPU_DRM_GPU_PLATFORM_SUPPORT_PROXY_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/ozone/public/gpu_platform_support.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace ui {
+
+class DrmGpuPlatformSupport;
+
+class DrmGpuPlatformSupportProxy : public GpuPlatformSupport {
+ public:
+  DrmGpuPlatformSupportProxy(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+      base::WeakPtr<DrmGpuPlatformSupport> impl);
+  ~DrmGpuPlatformSupportProxy() override;
+
+  // GpuPlatformSupport:
+  void OnChannelEstablished(IPC::Sender* sender) override;
+  IPC::MessageFilter* GetMessageFilter() override;
+
+  // IPC::Listener:
+  bool OnMessageReceived(const IPC::Message& message) override;
+
+ private:
+  scoped_refptr<IPC::MessageFilter> filter_;
+
+  DISALLOW_COPY_AND_ASSIGN(DrmGpuPlatformSupportProxy);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_DRM_GPU_DRM_GPU_PLATFORM_SUPPORT_PROXY_H_