GitLab

- AudioParam IDL test:
  Actually add the IDL to the test.  Also removed unused helpers.js.
- MediaElementAudioSourceNode
  Fix error because the expected result is mono, so only has one channel.
  However, this still fails on bots because there's no audio hardware to
  drive the online context.

Bug: 626703
Test: the-audioparam-interface/idl-test.html
Change-Id: I987ad1219da1b6b6ef677f2923416634fa281d5f
Reviewed-on: https://chromium-review.googlesource.com/920261
Commit-Queue: Raymond Toy <rtoy@chromium.org>
Reviewed-by: Hongchan Choi <hongchan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537856}