Merge third_party/libjingle/source/talk from https://chromium.googlesource.com/a/external/webrtc/trunk/talk.git at 7dc094518bd455c67e77eed579ebf70ed9b37db6

This commit was generated by merge_from_chromium.py.

Change-Id: I2cd303b7a253de8015044f479ec70cc343431ba8