Merge third_party/libjingle/source/talk from https://chromium.googlesource.com/external/webrtc/trunk/talk.git at 47740f2c26aea1b3b7830abdcba063a12a61d009

This commit was generated by merge_from_chromium.py.

Change-Id: I716b47abf872803a836ee46221e5d100dfbc3984