Implement periodic bandwidth probing in application-limited region.

webrtc/video_send_stream.h

Index: webrtc/video_send_stream.h
diff --git a/webrtc/video_send_stream.h b/webrtc/video_send_stream.h
index 74e9d5a5592af5d0868ae40d9f49278c2bbac3d2..0641ac4f6daceb7ded9aeaf0ea2992fbcdfc76e0 100644
--- a/webrtc/video_send_stream.h
+++ b/webrtc/video_send_stream.h
@@ -184,6 +184,9 @@ class VideoSendStream {
     // stream may send at a rate higher than the estimated available bitrate.
     bool suspend_below_min_bitrate = false;
 
+    // Enables periodic bandwidth probing in application-limited region.
+    bool periodic_bandwidth_probing = false;
+
    private:
     // Access to the copy constructor is private to force use of the Copy()
     // method for those exceptional cases where we do use it.