Impl mus::mojom::GpuService to enable using Chrome IPC version gpu CmdBuf in mus

components/mus/public/cpp/mus_public_export.h

Index: components/mus/public/cpp/mus_public_export.h
diff --git a/components/mus/public/cpp/mus_public_export.h b/components/mus/public/cpp/mus_public_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..6fa85e34bd28857e17520227619dbcfad929ad04
--- /dev/null
+++ b/components/mus/public/cpp/mus_public_export.h
@@ -0,0 +1,29 @@
+// Copyright (c) 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 COMPONENTS_MUS_PUBLIC_MUS_PUBLIC_EXPORT_H_
+#define COMPONENTS_MUS_PUBLIC_MUS_PUBLIC_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(MUS_PUBLIC_IMPLEMENTATION)
+#define MUS_PUBLIC_EXPORT __declspec(dllexport)
+#else
+#define MUS_PUBLIC_EXPORT __declspec(dllimport)
+#endif  // defined(MUS_COMMON_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(MUS_PUBLIC_IMPLEMENTATION)
+#define MUS_PUBLIC_EXPORT __attribute__((visibility("default")))
+#else
+#define MUS_PUBLIC_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define MUS_PUBLIC_EXPORT
+#endif
+
+#endif  // COMPONENTS_MUS_PUBLIC_MUS_PUBLIC_EXPORT_H_