Merge third_party/webrtc from https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git at 53545bbfc47f2cddb7038395369a0dcd457c8b34

This commit was generated by merge_from_chromium.py.

Change-Id: I9a04351d8f1bfde313d4565bd7f276b9684920d7