Reland of Update V8 to version 6.0.66. (patchset #2 id:40001 of...

Reland of Update V8 to version 6.0.66. (patchset #2 id:40001 of https://codereview.chromium.org/2842903003/ )

Reason for revert:
It was not the culprit for

BUG=chromium:715391

Original issue's description:
> Revert of Update V8 to version 6.0.66. (patchset #1 id:1 of https://codereview.chromium.org/2837923002/ )
>
> Reason for revert:
> Roll caused failed check in IsSane(), see bug for details
> BUG=715391
>
> Original issue's description:
> > Update V8 to version 6.0.66.
> >
> > Summary of changes available at:
> > https://chromium.googlesource.com/v8/v8/+log/9f6be2e9..ab1af916
> >
> > Please follow these instructions for assigning/CC'ing issues:
> > https://github.com/v8/v8/wiki/Triaging%20issues
> >
> > Please close rolling in case of a roll revert:
> > https://v8-roll.appspot.com/
> > This only works with a Google account.
> >
> > CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
> >
> > TBR=hablich@chromium.org,machenbach@chromium.org,kozyatinskiy@chromium.org,vogelheim@chromium.org
> >
> > Review-Url: https://codereview.chromium.org/2837923002
> > Cr-Commit-Position: refs/heads/master@{#466756}
> > Committed: https://chromium.googlesource.com/chromium/src/+/ddb812975b721aee41c39a12ac739eab0e8b053f
>
> TBR=hablich@chromium.org,kozyatinskiy@chromium.org,machenbach@chromium.org,vogelheim@chromium.org,v8-autoroll@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
>
> Review-Url: https://codereview.chromium.org/2842903003
> Cr-Commit-Position: refs/heads/master@{#467250}
> Committed: https://chromium.googlesource.com/chromium/src/+/650a5e0b7db28b5d4a69bb8a3be600cf636e662e

TBR=kozyatinskiy@chromium.org,machenbach@chromium.org,vogelheim@chromium.org,v8-autoroll@chromium.org,sashab@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=715391

Review-Url: https://codereview.chromium.org/2842913003
Cr-Commit-Position: refs/heads/master@{#467322}

DEPS

@@ -44,7 +44,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.
-  'v8_revision': '9f6be2e9e4279586cf484b669d1fc701c31a7fe2',
+  'v8_revision': 'fa3a1c7570ad09f941c31714d7d54c87439f4c39',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.