Fixing some issues with the direction attribute of m-lines in offers.

talk/app/webrtc/peerconnection.h

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 35 matching lines @@
 
 typedef std::vector<PortAllocatorFactoryInterface::StunConfiguration>
     StunConfigurations;
 typedef std::vector<PortAllocatorFactoryInterface::TurnConfiguration>
     TurnConfigurations;
 
 // Populates |session_options| from |rtc_options|, and returns true if options
 // are valid.
 // Send streams should already be added to |session_options| before this method
 // is called, as this affects the values of recv_audio and recv_video.
+// |currently_receiving_audio| and |currently_receiving_video| are used to
+// determine recv_audio and recv_video if the "offer_to_receive_#####" options
+// are undefined.
 bool ConvertRtcOptionsForOffer(
     const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
-    cricket::MediaSessionOptions* session_options);
+    cricket::MediaSessionOptions* session_options,
+    bool currently_receiving_audio,
+    bool currently_receiving_video);

[pthatcher1, 2015/10/15 06:02:03]

A few thoughts:

1.  The out pointer should still go last.
2.  This method should now be called something like CreateOfferOptions.  
3.  The I think instead of passing in currently_receiving_X, we should just pass
in X_recv_streams_, since that's what we're logically doing: create an offer
from existing streams.
4.  Should send streams and recv streams go together?  For example, if send
streams are already populated in session_options before calling this, should
recv streams also?  Or would it make sense to move populating send streams into
this function?

[Taylor Brandstetter, 2015/10/15 18:23:36]

Actually, I decided on a different approach that keeps this function simpler.
Really its intent WAS just "convert RTC options", mainly for the purpose of
existing unit tests. Hopefully, we can eventually (when talk and webrtc are
merged) just pass RTC options all the way down and this method will be
unnecessary.

 
 // Populates |session_options| from |constraints|, and returns true if all
 // mandatory constraints are satisfied.
 bool ParseConstraintsForAnswer(const MediaConstraintsInterface* constraints,
                                cricket::MediaSessionOptions* session_options);
 
 // Parses the URLs for each server in |servers| to build |stun_config| and
 // |turn_config|.
 bool ParseIceServers(const PeerConnectionInterface::IceServers& servers,
                      StunConfigurations* stun_config,
@@ skipping 320 matching lines @@
   // because its destruction fires signals (such as VoiceChannelDestroyed)
   // which will trigger some final actions in PeerConnection...
   rtc::scoped_ptr<WebRtcSession> session_;
   // ... But stats_ depends on session_ so it should be destroyed even earlier.
   rtc::scoped_ptr<StatsCollector> stats_;
 };
 
 }  // namespace webrtc
 
 #endif  // TALK_APP_WEBRTC_PEERCONNECTION_H_