Prevent busy-looping PacedSender on small packets.

webrtc/modules/pacing/bitrate_prober.h

Index: webrtc/modules/pacing/bitrate_prober.h
diff --git a/webrtc/modules/pacing/bitrate_prober.h b/webrtc/modules/pacing/bitrate_prober.h
index b3f52afeb6ed4ed5d5bd983424c1bc3216794bca..84fbc522fc9e3b2e4d87d19dc53741c82a549367 100644
--- a/webrtc/modules/pacing/bitrate_prober.h
+++ b/webrtc/modules/pacing/bitrate_prober.h
@@ -31,8 +31,10 @@ class BitrateProber {
   // TimeUntilNextProbe().
   bool IsProbing() const;
 
-  // Initializes a new probing session if the prober is allowed to probe.
-  void MaybeInitializeProbe(int bitrate_bps);
+  // Initializes a new probing session if the prober is allowed to probe. Does
+  // not initialize the prober unless the packet size is large enough to probe
+  // with.
+  void OnIncomingPacket(int bitrate_bps, size_t packet_size, int64_t now_ms);
 
   // Returns the number of milliseconds until the next packet should be sent to
   // get accurate probing.