Adding support for Unified Plan offer/answer negotiation.

webrtc/p2p/base/sessiondescription.h

Index: webrtc/p2p/base/sessiondescription.h
diff --git a/webrtc/p2p/base/sessiondescription.h b/webrtc/p2p/base/sessiondescription.h
index df9348d5814af05669ab135f9d6efe55649ff712..137e35cdd97fe475646bc66cf774a21b0244872b 100644
--- a/webrtc/p2p/base/sessiondescription.h
+++ b/webrtc/p2p/base/sessiondescription.h
@@ -56,6 +56,7 @@ struct ContentInfo {
   std::string type;
   bool rejected = false;
   bool bundle_only = false;
+  size_t msection_index = -1;

[Taylor Brandstetter, 2017/08/09 17:05:11]

It's redundant to store this inside ContentInfo, since it's implied by the
ContentInfo's index in SessionDescription::contents().

Where this is used in IsDtlsActive, you could do this instead:

int msection_index = content - &current_description->contents()[0];

Since subtraction of pointers gives you the number of elements that fit between
the two addresses.

Or you could just pass the index into the method.

[Zhi Huang, 2017/08/09 21:51:02]

This is a good point!

   ContentDescription* description = nullptr;
 };