Cast: Fix two video freezing problems

media/cast/transport/cast_transport_sender.h

 // Copyright 2013 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.
 
 // This is the main interface for the cast transport sender. The cast sender
 // handles the cast pipeline from encoded frames (both audio and video), to
 // encryption, packetization and transport.
 
 // Construction of the Cast Sender and the Cast Transport Sender should be done
 // in the following order:
 // 1. Create CastTransportSender.
 // 2. Create CastSender (accepts CastTransportSender as an input).
 // 3. Call CastTransportSender::SetPacketReceiver to ensure that the packets
 //    received by the CastTransportSender will be sent to the CastSender.
-// 4. Initialize audio and/or video.
-// Steps 3 & 4 can be done interchangeably.
+// Steps 3 can be done interchangeably.
 
 // Destruction: The CastTransportSender is assumed to be valid as long as the
 // CastSender is alive. Therefore the CastSender should be destructed before the
 // CastTransportSender.
 // This also works when the CastSender acts as a receiver for the RTCP packets
 // due to the weak pointers in the ReceivedPacket method in cast_sender_impl.cc.
 
 #ifndef MEDIA_CAST_TRANSPORT_CAST_TRANSPORT_SENDER_H_
 #define MEDIA_CAST_TRANSPORT_CAST_TRANSPORT_SENDER_H_
 
@@ skipping 35 matching lines @@
       const net::IPEndPoint& remote_end_point,
       const CastTransportStatusCallback& status_callback,
       const BulkRawEventsCallback& raw_events_callback,
       base::TimeDelta raw_events_callback_interval,
       const scoped_refptr<base::SingleThreadTaskRunner>& transport_task_runner);
 
   virtual ~CastTransportSender() {}
 
   // Audio/Video initialization.
   // Encoded frames cannot be transmitted until the relevant initialize method
-  // is called.
+  // is called. Usually called by CastSender.
   virtual void InitializeAudio(const CastTransportAudioConfig& config) = 0;
 
   virtual void InitializeVideo(const CastTransportVideoConfig& config) = 0;
 
   // Sets the Cast packet receiver. Should be called after creation on the
   // Cast sender. Packets won't be received until this function is called.
   virtual void SetPacketReceiver(
       const PacketReceiverCallback& packet_receiver) = 0;
 
   // The following two functions handle the encoded media frames (audio and
@@ skipping 26 matching lines @@
 
   virtual void SubscribeVideoRtpStatsCallback(
       const CastTransportRtpStatistics& callback) = 0;
 };
 
 }  // namespace transport
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_TRANSPORT_CAST_TRANSPORT_SENDER_H_