Avoid URL allocation for GetContentSettingFromRules fast path

Avoid URL allocation for GetContentSettingFromRules fast path

This function is called all the time for both image and script loads from
Blink, resulting in extra WebURL -> GURL allocations. This is
particularly bad for images loaded via data URLs which can be big.

BUG=657978

[Charlie Harrison, 2017-01-05 21:40:59]

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

[commit-bot: I haz the power, 2017-01-05 21:41:24]

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

[Charlie Harrison, 2017-01-05 21:47:03]

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

[Charlie Harrison, 2017-01-05 21:47:04]

jochen: PTAL? Probably we can be smarter about how often we call this from Blink
(images call this twice per load :/), but for now I think this is a good
band-aid.

Profiling on Linux shows that this accounts for roughly 96% of
ResourceFetcher::requestResource for a ~1.5MB data image, and ~11% of the cost
of updating the image src (a majority of the time is spent parsing).

[commit-bot: I haz the power, 2017-01-05 23:01:28]

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

[commit-bot: I haz the power, 2017-01-05 23:01:28]

Dry run: This issue passed the CQ dry run.

[jochen (gone - plz use gerrit), 2017-01-09 08:42:29]

lgtm

can you please file a bug about invoking this twice per load?

[Charlie Harrison, 2017-01-09 13:14:49]

On 2017/01/09 08:42:29, jochen wrote:
> lgtm
> 
> can you please file a bug about invoking this twice per load?

I realized we only invoke this twice (synchronously) for images loaded from
memory cache, but  I filed crbug.com/679328 about it.

Thanks for the review!

[Charlie Harrison, 2017-01-09 13:15:08]

The CQ bit was checked by csharrison@chromium.org

[commit-bot: I haz the power, 2017-01-09 13:15:20]

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, 2017-01-09 14:01:27]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1483967708166970, "parent_rev":
"5adef79d6f465dddc30e88db148c5b69c7059448", "commit_rev":
"0b43ca02fdfd66fbd9a1a35dfd74be402f80e77d"}

[commit-bot: I haz the power, 2017-01-09 14:06:17]

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

[commit-bot: I haz the power, 2017-01-09 14:06:19]

Prior attempt to commit was detected, but we were not able to check whether the
issue was successfully committed. Please check Git history manually and re-check
CQ or close this issue as needed.

[Charlie Harrison, 2017-01-09 14:23:30]

On 2017/01/09 14:06:19, commit-bot: I haz the power wrote:
> Prior attempt to commit was detected, but we were not able to check whether
the
> issue was successfully committed. Please check Git history manually and
re-check
> CQ or close this issue as needed.

Manually, it looks like this successfully landed. Odd. I'll close.

[Charlie Harrison, 2017-01-09 14:23:37]

Description was changed from

==========
Avoid URL allocation for GetContentSettingFromRules fast path

This function is called all the time for both image and script loads from
Blink, resulting in extra WebURL -> GURL allocations. This is
particularly bad for images loaded via data URLs which can be big.

BUG=657978
==========

to

==========
Avoid URL allocation for GetContentSettingFromRules fast path

This function is called all the time for both image and script loads from
Blink, resulting in extra WebURL -> GURL allocations. This is
particularly bad for images loaded via data URLs which can be big.

BUG=657978
==========