tree c3f9d0f52111617f532ce0e11295f86bde33707f
parent c61217944d70f81ef03b7921ed02624038ca69e8
author mcasas <mcasas@chromium.org> 1463787554 -0700
committer Commit bot <commit-bot@chromium.org> 1463787661 +0000

MediaCaptureFromElement: add support for audio captureStream().

This CL extends support for capturing the audio part of
a <video> or <audio> tags ( "capture" here means creating
a MediaStream out of the HTMLElement)

It introduces an HtmlAudioCapturerSource is-a AudioCapturerSource
wrapped into an ExternalMediaStreamAudioSource to produce data
towards the audio track.

HtmlAudioCapturerSource also plugs into the
WebMediaPlayer's WebAudioSourceProviderImpl to get
a copy of the audio being rendered.

Unit tests are added, and the existing LayouTests
revamped (and split into several files for clarity).

BUG=569976, 575492

TEST= run chromium with
 --enable-blink-features=MediaCaptureFromVideo
 against e.g.
https://rawgit.com/Miguelao/demos/master/videoelementcapture.html

Review-Url: https://codereview.chromium.org/1599533003
Cr-Commit-Position: refs/heads/master@{#395205}