Revert of Delete unused class/template ScopedMessageData.

webrtc/base/messagequeue.h

Index: webrtc/base/messagequeue.h
diff --git a/webrtc/base/messagequeue.h b/webrtc/base/messagequeue.h
index 14cf29bb28d87ffe5b011d7101b4ddc27157fc73..628ce4433b824396c952400836d39bd8df023a6c 100644
--- a/webrtc/base/messagequeue.h
+++ b/webrtc/base/messagequeue.h
@@ -94,6 +94,19 @@
   T data_;
 };
 
+// Like TypedMessageData, but for pointers that require a delete.
+template <class T>
+class ScopedMessageData : public MessageData {
+ public:
+  explicit ScopedMessageData(T* data) : data_(data) { }
+  const std::unique_ptr<T>& data() const { return data_; }
+  std::unique_ptr<T>& data() { return data_; }
+
+ private:
+  std::unique_ptr<T> data_;
+};
+
+// Like ScopedMessageData, but for reference counted pointers.
 template <class T>
 class ScopedRefMessageData : public MessageData {
  public: