Revert of [DevTools] Capabilities on browser side. (patchset #3 id:40001 of https://codereview.chromium.org/
1208993002/)
Reason for revert:
Decided against this path.
Original issue's description:
> [DevTools] Capabilities on browser side.
>
> BUG=504412
>
> Committed: https://crrev.com/
ec5a24bd9aff8645121d06c72ca93576e4a30128
> Cr-Commit-Position: refs/heads/master@{#336772}
TBR=pfeldman@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=504412
Review URL: https://codereview.chromium.org/
1217943005
Cr-Commit-Position: refs/heads/master@{#336794}