Consistently cache ElementData::length() before loops

Consistently cache ElementData::length() before loops

Consistently cache ElementData::length() before loops as this method is not
a simple getter (it contains a conditional branch) and we don't want to call
it for each iteration of the loop.

Previously, it was only cached before some of the loops. This CL makes this
consistent. Also, use length for the variable instead of len, as we prefer to
avoid abbreviations, as per coding style.

Same thing for Element::attributeCount() as it calls ElementData::length().

R=adamk, eseidel

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=167794

[esprehn, 2014-02-24 19:52:55]

lgtm, we should probably just add an iterator someday instead.

Can you add a comment to ElementData.h and Element.h that you should cache these
values? We often undo these locals because they just look like clutter.

[Inactive, 2014-02-24 20:18:36]

On 2014/02/24 19:52:55, esprehn wrote:
> lgtm, we should probably just add an iterator someday instead.
> 
> Can you add a comment to ElementData.h and Element.h that you should cache
these
> values? We often undo these locals because they just look like clutter.

Done.

[Inactive, 2014-02-24 20:18:57]

The CQ bit was checked by ch.dumez@samsung.com

[commit-bot: I haz the power, 2014-02-24 20:19:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/177613003/110001

[adamk, 2014-02-24 20:46:21]

Agreed that the right way forward is to wrap this stuff in an iterator, it's
going to be fragile to rely on callers to treat these as expensive...

[Inactive, 2014-02-24 20:50:57]

On 2014/02/24 20:46:21, adamk wrote:
> Agreed that the right way forward is to wrap this stuff in an iterator, it's
> going to be fragile to rely on callers to treat these as expensive...

Yes, I agree as well. I'll look into it soon.

[commit-bot: I haz the power, 2014-02-24 23:01:13]

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

[commit-bot: I haz the power, 2014-02-24 23:01:14]

Retried try job too often on mac_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_blink_...

[Inactive, 2014-02-24 23:24:44]

The CQ bit was checked by ch.dumez@samsung.com

[commit-bot: I haz the power, 2014-02-24 23:25:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/177613003/110001

[commit-bot: I haz the power, 2014-02-25 01:09:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/177613003/110001

[commit-bot: I haz the power, 2014-02-25 03:01:12]

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

[commit-bot: I haz the power, 2014-02-25 03:01:13]

Retried try job too often on mac_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_blink_...

[Inactive, 2014-02-25 03:08:54]

The CQ bit was checked by ch.dumez@samsung.com

[commit-bot: I haz the power, 2014-02-25 03:09:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/177613003/110001

[commit-bot: I haz the power, 2014-02-25 04:53:13]

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

[commit-bot: I haz the power, 2014-02-25 04:53:14]

Retried try job too often on mac_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_blink_...

[Inactive, 2014-02-25 13:59:58]

The CQ bit was checked by ch.dumez@samsung.com

[commit-bot: I haz the power, 2014-02-25 14:00:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/177613003/180001

[commit-bot: I haz the power, 2014-02-25 15:54:56]

Change committed as 167794