This reverts commit 499976c54a2b086bbde54ae137d0ac4adb3cd427.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 668149 as the
culprit for flakes in the build cycles as shown on:
https://analysis.chromium.org/p/chromium/flake-portal/analysis/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vNDk5OTc2YzU0YTJiMDg2YmJkZTU0YWUxMzdkMGFjNGFkYjNjZDQyNww

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.mac/WebKit%20Mac10.13%20%28retina%29/15474

Sample Failed Step: webkit_layout_tests on ATI GPU on Mac Retina on Mac-10.13.6

Sample Flaky Test: external/wpt/webaudio/the-audio-api/the-convolvernode-interface/active-processing.https.html

Original change's description:
> Active Processing for ConvolverNode
>
> The ConvolverNode should output a single channel of silence when it is not
> actively processing.  Active processing is already supported and just needed
> to have the convolver output a single channel of silence when it is
> constructed, before anything is connected to it.
>
> Bug: 971389
> Change-Id: Icc894cd7ea6dec60a1eccb0fa4a3aea68ac5b51f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1644899
> Commit-Queue: Raymond Toy <rtoy@chromium.org>
> Reviewed-by: Hongchan Choi <hongchan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#668149}

Change-Id: Ie7fedee332ca167c3dfd4fd99142de89234ff03a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 971389
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1653924
Cr-Commit-Position: refs/heads/master@{#668243}