Cache length in ElementData::getAttributeItemIndex() for performance

Cache length in ElementData::getAttributeItemIndex() for performance

Cache length in ElementData::getAttributeItemIndex() for performance.
We should avoid to call ElementData::length() in a loop as it hides an
if check to see if the ElementData is unique or not.

I see a 2.8% improvement on Bindings/id-setter.html performance test on
Linux desktop. This minimizes the performance regression caused by
r157508.

R=arv, esprehn
BUG=293663
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=163216

[Inactive, 2013-12-04 19:14:30]

https://codereview.chromium.org/105163003/diff/1/Source/core/dom/ElementData.h
File Source/core/dom/ElementData.h (right):

https://codereview.chromium.org/105163003/diff/1/Source/core/dom/ElementData....
Source/core/dom/ElementData.h:201: unsigned len = length();
Note that we already cache the length in this method.

[arv (Not doing code reviews), 2013-12-04 19:43:47]

LGTM

[commit-bot: I haz the power, 2013-12-04 19:45:26]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/105163003/1

[commit-bot: I haz the power, 2013-12-04 20:31:46]

Retried try job too often on linux_blink for step(s) blink_platform_unittests,
webkit_lint, webkit_python_tests, webkit_tests, webkit_unit_tests, wtf_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[esprehn, 2013-12-04 20:35:37]

Can you add a comment before landing? Someone is just going to remove this
in the future because they won't know.

To unsubscribe from this group and stop receiving emails from it, send an email
to blink-reviews+unsubscribe@chromium.org.

[Inactive, 2013-12-04 20:40:17]

On 2013/12/04 20:35:37, esprehn wrote:
> Can you add a comment before landing? Someone is just going to remove this
> in the future because they won't know.
> 
> To unsubscribe from this group and stop receiving emails from it, send an
email
> to mailto:blink-reviews+unsubscribe@chromium.org.

Done.

Sadly the tree is in a bad state and neither me or the try bots are able to
build. I will for the tree to get fixed before landing.

[commit-bot: I haz the power, 2013-12-05 00:49:03]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/105163003/20001

[commit-bot: I haz the power, 2013-12-05 04:13:11]

Change committed as 163216