Revert of Add PassPaintVisualRectToCompositor feature flag. (patchset #3...

Revert of Add PassPaintVisualRectToCompositor feature flag. (patchset #3 id:40001 of https://codereview.chromium.org/1410573008/ )

Reason for revert:
Tentative revert since it seems to break http://build.chromium.org/p/chromium.linux/builders/Android%20Tests%20%28dbg%29/builds/31016.

cc_unittests

ThreadedChannelTestCommit.RunMultiThread_DirectRenderer.

Original issue's description:
> Add PassPaintVisualRectToCompositor feature flag.
>
> BUG=529938
>
> Committed: https://crrev.com/e8cc107c99f8dea17c02c677270e4e8af3f943c7
> Cr-Commit-Position: refs/heads/master@{#357052}

TBR=chrishtr@chromium.org,pdr@chromium.org,vmpstr@chromium.org,wkorman@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=529938

Review URL: https://codereview.chromium.org/1424783004

Cr-Commit-Position: refs/heads/master@{#357072}

third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in

@@ -119,7 +119,6 @@ OrientationEvent
 ForceOverlayFullscreenVideo
 OverlayScrollbars
 PagePopup status=stable
-PassPaintVisualRectToCompositor
 PathOpsSVGClipping status=stable
 PerformanceObserver status=experimental
 Permissions status=stable