Revert of Removed support deprecated (//@|/*@) source(URL|MappingURL)=

Revert of Removed support deprecated (//@|/*@) source(URL|MappingURL)= (patchset #1 id:1 of https://codereview.chromium.org/1474543005/ )

Reason for revert:
Failing layout tests:

inspector/tracing/timeline-event-causes.html
virtual/syncpaint/inspector/tracing/timeline-event-causes.html
inspector/animation/animation-timeline-fill.html
virtual/threaded/inspector/tracing/timeline-event-causes.html
inspector/tracing/timeline-script-id.html
inspector/sources/debugger-ui/source-url-comment.html
inspector/console/console-log-linkify-stack-in-errors.html
virtual/syncpaint/inspector/tracing/timeline-script-id.html
virtual/threaded/inspector/tracing/timeline-script-id.html

Original issue's description:
> Removed support deprecated (//@|/*@) source(URL|MappingURL)=
>
> LOG=Y
> BUG=chromium:558998
> R=yangguo@chromium.org
>
> Committed: https://crrev.com/c1e5f005d79c436d90f474f8bc6448c4555a619f
> Cr-Commit-Position: refs/heads/master@{#32249}

TBR=machenbach@chromium.org,kozyatinskiy@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:558998
Committed: https://crrev.com/1db01d6d5d33842536b19fb8a2767dd5f6bdaa3c
Cr-Commit-Position: refs/heads/master@{#32259}

[Yang, 2015-11-25 10:26:57]

Created Revert of Removed support deprecated (//@|/*@) source(URL|MappingURL)=

[commit-bot: I haz the power, 2015-11-25 10:27:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1481513002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1481513002/1

[commit-bot: I haz the power, 2015-11-25 10:27:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-25 10:28:08]

Patchset 1 (id:??) landed as
https://crrev.com/1db01d6d5d33842536b19fb8a2767dd5f6bdaa3c
Cr-Commit-Position: refs/heads/master@{#32259}

[Michael Achenbach, 2015-11-25 12:21:14]

Looks like this was the cause. Cycled green now:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/bui...

Please request rebase upstream first and add one of the chromium trybots on
reland (they'll execute the layout tests).