commit 913419cf02929813a7ca8d1584fb42fc55d5e10d
author mcasas <mcasas@chromium.org> Fri Apr 29 16:40:00 2016
committer Commit bot <commit-bot@chromium.org> Fri Apr 29 16:41:31 2016
tree 1b30542119979df5688a0b6a25331a03c494c188
parent 53cbed151cea16f4d27cc887a272d9e672c41b75

MediaRecorderHandler and WebmMuxer: add support for H264.

This CL adds support for H264 codec type in both WebmMuxer
and MediaRecorderHandler.

Support for H264 (and other) codecs was added to libwebm
(which underlies WebmMuxer) in [1], by flipping the Doc Type
indication of the webm file from "webm" to "matroska".

MediaRecorder Handler basically just expands the boolean
indication vp9 yes/no into using the enum class CodecId
from VideoTrackRecorder.

[1] https://chromium-review.googlesource.com/340298

BUG=601636
TEST= extended unit tests playground CL @ https://crrev.com/1886123002/

Review-Url: https://codereview.chromium.org/1920483002
Cr-Commit-Position: refs/heads/master@{#390670}