Include harmony-string-padding.js in the context snapshot

Include harmony-string-padding.js in the context snapshot

The attached chromium bug suggests that turning this on via a flag
regressed a perf test. Having previously run into slowdowns due
to experimental JS natives, my suspicion is that this regression
can be fixed by including the new builtins in the snapshot.
My intention is to land this patch to see if the regression
goes away on the bots.

Given the nature of this feature, it seems low-risk to remove
the runtime flag. If need be, it would be trivial to craft
a patch to remove these two methods from String.prototype
if we run into web compat issues during the release (note
that no release branch has yet picked up this feature).

BUG=v8:4954, chromium:677444
Review-Url: https://codereview.chromium.org/2610853010
Cr-Commit-Position: refs/heads/master@{#42111}
Committed: https://chromium.googlesource.com/v8/v8/+/02149d89a5a9715309d3fc786466224958a66c9c

[adamk, 2017-01-05 23:40:11]

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

[commit-bot: I haz the power, 2017-01-05 23:40:22]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[adamk, 2017-01-05 23:40:36]

adamk@chromium.org changed reviewers:
+ caitp@igalia.com, littledan@chromium.org

[commit-bot: I haz the power, 2017-01-06 00:09:01]

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

[commit-bot: I haz the power, 2017-01-06 00:09:01]

Dry run: This issue passed the CQ dry run.

[Dan Ehrenberg, 2017-01-06 03:08:27]

lgtm

Sounds like this should be our standard practice for all JS builtins under
development when it comes time to ship them, until we get rid of JS builtins.

[adamk, 2017-01-06 18:54:07]

On 2017/01/06 03:08:27, Dan Ehrenberg wrote:
> lgtm
> 
> Sounds like this should be our standard practice for all JS builtins under
> development when it comes time to ship them, until we get rid of JS builtins.

If this indeed fixes the regression, I agree (though I wouldn't expect a lot
more JS builtins to come into existence at this point).

[adamk, 2017-01-06 18:54:12]

The CQ bit was checked by adamk@chromium.org

[commit-bot: I haz the power, 2017-01-06 18:54:24]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-06 18:56:01]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1483728852655960,
"parent_rev": "2c60a1facf13fed597fcdc30b53d34ec13d44927", "commit_rev":
"02149d89a5a9715309d3fc786466224958a66c9c"}

[commit-bot: I haz the power, 2017-01-06 18:56:06]

Description was changed from

==========
Include harmony-string-padding.js in the context snapshot

The attached chromium bug suggests that turning this on via a flag
regressed a perf test. Having previously run into slowdowns due
to experimental JS natives, my suspicion is that this regression
can be fixed by including the new builtins in the snapshot.
My intention is to land this patch to see if the regression
goes away on the bots.

Given the nature of this feature, it seems low-risk to remove
the runtime flag. If need be, it would be trivial to craft
a patch to remove these two methods from String.prototype
if we run into web compat issues during the release (note
that no release branch has yet picked up this feature).

BUG=v8:4954, chromium:677444
==========

to

==========
Include harmony-string-padding.js in the context snapshot

The attached chromium bug suggests that turning this on via a flag
regressed a perf test. Having previously run into slowdowns due
to experimental JS natives, my suspicion is that this regression
can be fixed by including the new builtins in the snapshot.
My intention is to land this patch to see if the regression
goes away on the bots.

Given the nature of this feature, it seems low-risk to remove
the runtime flag. If need be, it would be trivial to craft
a patch to remove these two methods from String.prototype
if we run into web compat issues during the release (note
that no release branch has yet picked up this feature).

BUG=v8:4954, chromium:677444

Review-Url: https://codereview.chromium.org/2610853010
Cr-Commit-Position: refs/heads/master@{#42111}
Committed:
https://chromium.googlesource.com/v8/v8/+/02149d89a5a9715309d3fc786466224958a...
==========

[commit-bot: I haz the power, 2017-01-06 18:56:07]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/02149d89a5a9715309d3fc786466224958a...