Refactor script position calculation

Refactor script position calculation

Script position calculation logic (i.e. line & column numbers for a
given code position) is now based on a single method
Script::GetPositionInfo(). Refactored related code in isolate.cc and
js/messages.js to use the new method. The line_ends accessor is still
in use by chromium and thus cannot be removed yet.

R=yangguo@chromium.org
BUG=

Committed: https://crrev.com/94ad3b1826fdd08866213220e9ef24d981ed0399
Cr-Commit-Position: refs/heads/master@{#36458}

[jgruber, 2016-05-23 11:47:56]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-05-23 11:48:02]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2002993002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2002993002/1

[commit-bot: I haz the power, 2016-05-23 12:20:11]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-23 12:20:12]

Dry run: This issue passed the CQ dry run.

[jgruber, 2016-05-23 13:11:01]

One more time around. The previous version of this patch caused crashes on
gc-stress bots because it dereferenced unhandlified this pointers.

[Yang, 2016-05-23 18:25:35]

On 2016/05/23 13:11:01, jgruber1 wrote:
> One more time around. The previous version of this patch caused crashes on
> gc-stress bots because it dereferenced unhandlified this pointers.

lgtm.

[jgruber, 2016-05-24 06:37:45]

The CQ bit was checked by jgruber@chromium.org

[commit-bot: I haz the power, 2016-05-24 06:37:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2002993002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2002993002/1

[commit-bot: I haz the power, 2016-05-24 06:40:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-24 06:42:40]

Description was changed from

==========
Refactor script position calculation

Script position calculation logic (i.e. line & column numbers for a
given code position) is now based on a single method
Script::GetPositionInfo(). Refactored related code in isolate.cc and
js/messages.js to use the new method. The line_ends accessor is still
in use by chromium and thus cannot be removed yet.

R=yangguo@chromium.org
BUG=
==========

to

==========
Refactor script position calculation

Script position calculation logic (i.e. line & column numbers for a
given code position) is now based on a single method
Script::GetPositionInfo(). Refactored related code in isolate.cc and
js/messages.js to use the new method. The line_ends accessor is still
in use by chromium and thus cannot be removed yet.

R=yangguo@chromium.org
BUG=

Committed: https://crrev.com/94ad3b1826fdd08866213220e9ef24d981ed0399
Cr-Commit-Position: refs/heads/master@{#36458}
==========

[commit-bot: I haz the power, 2016-05-24 06:42:41]

Patchset 1 (id:??) landed as
https://crrev.com/94ad3b1826fdd08866213220e9ef24d981ed0399
Cr-Commit-Position: refs/heads/master@{#36458}