Add a histogram metric tracking for how long audio RTP packets are sent

webrtc/audio/audio_send_stream_unittest.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 215 matching lines @@
           .Times(1);
     } else {
       EXPECT_CALL(*channel_proxy_, RegisterSenderCongestionControlObjects(
                                        &fake_transport_, Eq(nullptr)))
           .Times(1);
     }
     EXPECT_CALL(*channel_proxy_, SetBitrate(_, _))
         .Times(1);
     EXPECT_CALL(*channel_proxy_, ResetSenderCongestionControlObjects())
         .Times(1);
-    EXPECT_CALL(*channel_proxy_, RegisterExternalTransport(nullptr)).Times(1);

[ossu, 2017/07/14 11:13:15]

This is odd. Why would the test want to set the external transport to nullptr
(rather than DeRegistering the external transport)? Also, with a nullptr
external transport, I'd expect we wouldn't want to wrap it with a
TimedTransport.

[saza WebRTC, 2017/07/17 14:27:29]

Done.

+    EXPECT_CALL(*channel_proxy_, RegisterExternalTransport(_)).Times(1);
     EXPECT_CALL(*channel_proxy_, DeRegisterExternalTransport()).Times(1);
     EXPECT_CALL(*channel_proxy_, SetRtcEventLog(testing::NotNull())).Times(1);
     EXPECT_CALL(*channel_proxy_, SetRtcEventLog(testing::IsNull()))
         .Times(1);  // Destructor resets the event log
     EXPECT_CALL(*channel_proxy_, SetRtcpRttStats(&rtcp_rtt_stats_)).Times(1);
     EXPECT_CALL(*channel_proxy_, SetRtcpRttStats(testing::IsNull()))
         .Times(1);  // Destructor resets the rtt stats.
   }
 
   void SetupMockForSetupSendCodec(bool expect_set_encoder_call) {
@@ skipping 316 matching lines @@
     EXPECT_CALL(*helper.channel_proxy(), RegisterSenderCongestionControlObjects(
         helper.transport(), Ne(nullptr)))
         .Times(1);
   }
   send_stream.Reconfigure(new_config);
 }
 
 
 }  // namespace test
 }  // namespace webrtc