+ * @brief Send message to acknowledge for completing window rotation with current window orientation.
+ *
+ * If this function is called, the message is sent to render thread, then mSurfaceRectChanged in scene-graph-scene is set with true.
+ * After that, render thread checks whether window rotation event is received, mSurfaceRectChanged and the neccessary flag are set.
+ * If they are all true, rotation done function is called to complete window rotation.
+ */
+ void SetRotationCompletedAcknowledgement();
+
+ /**
+ * @brief Query wheter is set to acknowledge for completing surface rotation.
+ * @return true it should be acknowledged.
+ *
+ * If SetRotationCompletedAcknowledgement() is called and the related message is received to scene-graph-scene,
+ * then mSurfaceRectChanged in scene-graph-scene is set with true.
+ *
+ * When this function is called, the mSurfaceRectChanged in scene-graph-scene is return.
+ * Then, the flag will be reset.
+ *
+ * @note This function should be not called the application's main thread.
+ * Because this function should be called in windwow surface's postrender() function to complete window rotation manually.
+ */
+ bool IsRotationCompletedAcknowledgementSet() const;
+
+ /**