[Cast] In Audio/VideoSender, drop frames when too-long a duration is in-flight.

media/cast/sender/frame_sender.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cast/sender/frame_sender.h"
 
 namespace media {
 namespace cast {
 namespace {
 const int kMinSchedulingDelayMs = 1;
@@ skipping 33 matching lines @@
       FROM_HERE,
       base::Bind(&FrameSender::SendRtcpReport, weak_factory_.GetWeakPtr(),
                  true),
       time_to_next);
 }
 
 void FrameSender::SendRtcpReport(bool schedule_future_reports) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
   const base::TimeTicks now = cast_environment_->Clock()->NowTicks();
   uint32 now_as_rtp_timestamp = 0;
-  if (rtp_timestamp_helper_.GetCurrentTimeAsRtpTimestamp(
-          now, &now_as_rtp_timestamp)) {
+  if (rtp_timestamp_helper_.EstimateRtpTimestamp(now, &now_as_rtp_timestamp)) {
     transport_sender_->SendSenderReport(ssrc_, now, now_as_rtp_timestamp);
   } else {
     // |rtp_timestamp_helper_| should have stored a mapping by this point.
     NOTREACHED();
   }
   if (schedule_future_reports)
     ScheduleNextRtcpReport();
 }
 
 void FrameSender::OnReceivedRtt(base::TimeDelta rtt,
@@ skipping 13 matching lines @@
   max_unacked_frames_ =
       std::min(kMaxUnackedFrames,
                1 + static_cast<int>(target_playout_delay_ *
                                     max_frame_rate_ /
                                     base::TimeDelta::FromSeconds(1)));
   send_target_playout_delay_ = true;
 }
 
 }  // namespace cast
 }  // namespace media