Only use paced packets for estimating bitrate probes.

BUG=4778
R=mflodman@webrtc.org, solenberg@webrtc.org

Review URL: https://codereview.webrtc.org/1188823007.

Cr-Commit-Position: refs/heads/master@{#9463}
diff --git a/webrtc/video_engine/vie_channel_group.cc b/webrtc/video_engine/vie_channel_group.cc
index f5e83ac..768365c 100644
--- a/webrtc/video_engine/vie_channel_group.cc
+++ b/webrtc/video_engine/vie_channel_group.cc
@@ -55,10 +55,11 @@
 
   void IncomingPacket(int64_t arrival_time_ms,
                       size_t payload_size,
-                      const RTPHeader& header) override {
+                      const RTPHeader& header,
+                      bool was_paced) override {
     CriticalSectionScoped cs(crit_sect_.get());
     PickEstimatorFromHeader(header);
-    rbe_->IncomingPacket(arrival_time_ms, payload_size, header);
+    rbe_->IncomingPacket(arrival_time_ms, payload_size, header, was_paced);
   }
 
   int32_t Process() override {