Add ShareGroup stub

gpu/command_buffer/client/share_group.h

Index: gpu/command_buffer/client/share_group.h
diff --git a/gpu/command_buffer/client/share_group.h b/gpu/command_buffer/client/share_group.h
new file mode 100644
index 0000000000000000000000000000000000000000..8ce940ab6bb2a46124baa326300da1d089aa481e
--- /dev/null
+++ b/gpu/command_buffer/client/share_group.h
@@ -0,0 +1,32 @@
+// Copyright (c) 2012 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_COMMAND_BUFFER_CLIENT_SHARE_GROUP_H_
+#define GPU_COMMAND_BUFFER_CLIENT_SHARE_GROUP_H_
+
+#include "../client/ref_counted.h"
+#include "gles2_impl_export.h"
+
+namespace gpu {
+namespace gles2 {
+
+// ShareGroup manages shared resources for contexts that are sharing resources.
+class GLES2_IMPL_EXPORT ShareGroup
+    : public gpu::RefCountedThreadSafe<ShareGroup> {
+ public:
+  typedef scoped_refptr<ShareGroup> Ref;
+
+  ShareGroup();
+  ~ShareGroup();
+
+  bool Initialize();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ShareGroup);
+};
+
+}  // namespace gles2
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_CLIENT_SHARE_GROUP_H_