Pass null WebString for empty WebSecurityOrigin::suborigin()

Pass null WebString for empty WebSecurityOrigin::suborigin()

This removes a bunch of calls which end up with a WebString pointing to
the global empty string, which was showing up in profiles.

BUG=348655
Committed: https://crrev.com/7ba4ff4fba27c016a606cd3c552d9cd7ebdba09e
Cr-Commit-Position: refs/heads/master@{#438070}

[Charlie Harrison, 2016-12-07 19:19:48]

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

[commit-bot: I haz the power, 2016-12-07 19:20:11]

Dry run: 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, 2016-12-07 21:18:02]

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

[commit-bot: I haz the power, 2016-12-07 21:18:03]

Dry run: This issue passed the CQ dry run.

[Charlie Harrison, 2016-12-12 20:03:04]

csharrison@chromium.org changed reviewers:
+ kinuko@chromium.org

[Charlie Harrison, 2016-12-12 20:03:05]

kinuko: is this reasonable? The ternary operator forces evaluation to a String,
causing a StringImpl construction and strlen() calls on the literal which was
showing up in profiles, despite it being empty.

[kinuko, 2016-12-13 03:45:44]

On 2016/12/12 20:03:05, Charlie Harrison wrote:
> kinuko: is this reasonable? The ternary operator forces evaluation to a
String,
> causing a StringImpl construction and strlen() calls on the literal which was
> showing up in profiles, despite it being empty.

Curious if directly using emptyString() changes the numbers?  LGTM, regardless.

[Charlie Harrison, 2016-12-13 03:48:53]

On 2016/12/13 03:45:44, kinuko wrote:
> On 2016/12/12 20:03:05, Charlie Harrison wrote:
> > kinuko: is this reasonable? The ternary operator forces evaluation to a
> String,
> > causing a StringImpl construction and strlen() calls on the literal which
was
> > showing up in profiles, despite it being empty.
> 
> Curious if directly using emptyString() changes the numbers?  LGTM,
regardless.

Judging by the profile, I think it does, we just go through a lot of boilerplate
to get there. I've seen this sort of thing elsewhere in profiles so I might do a
more in-depth analysis for dealing with empty strings in Blink. Implicit
conversions, etc. sometimes make this more expensive than they first seem.

[Charlie Harrison, 2016-12-13 03:48:57]

The CQ bit was checked by csharrison@chromium.org

[commit-bot: I haz the power, 2016-12-13 03:49:33]

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, 2016-12-13 05:47:11]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481600937378000, "parent_rev":
"bbc6fdf9a02cbf6b1dec1cf378f272264c04c2e4", "commit_rev":
"1e62924f26b0d11062a9bc7be54de158eb3ce333"}

[commit-bot: I haz the power, 2016-12-13 05:47:41]

Description was changed from

==========
Pass null WebString for empty WebSecurityOrigin::suborigin()

This removes a bunch of calls which end up with a WebString pointing to
the global empty string, which was showing up in profiles.

BUG=348655
==========

to

==========
Pass null WebString for empty WebSecurityOrigin::suborigin()

This removes a bunch of calls which end up with a WebString pointing to
the global empty string, which was showing up in profiles.

BUG=348655

Review-Url: https://codereview.chromium.org/2555983003
==========

[commit-bot: I haz the power, 2016-12-13 05:47:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-13 05:49:10]

Description was changed from

==========
Pass null WebString for empty WebSecurityOrigin::suborigin()

This removes a bunch of calls which end up with a WebString pointing to
the global empty string, which was showing up in profiles.

BUG=348655

Review-Url: https://codereview.chromium.org/2555983003
==========

to

==========
Pass null WebString for empty WebSecurityOrigin::suborigin()

This removes a bunch of calls which end up with a WebString pointing to
the global empty string, which was showing up in profiles.

BUG=348655

Committed: https://crrev.com/7ba4ff4fba27c016a606cd3c552d9cd7ebdba09e
Cr-Commit-Position: refs/heads/master@{#438070}
==========

[commit-bot: I haz the power, 2016-12-13 05:49:11]

Patchset 1 (id:??) landed as
https://crrev.com/7ba4ff4fba27c016a606cd3c552d9cd7ebdba09e
Cr-Commit-Position: refs/heads/master@{#438070}