Optimize Element::attributeChanged()

Optimize Element::attributeChanged()

This patch makes style attribute and presentation attribute checks conditional, meaning that these checks are not done for the attributes that we already know have other types.
The reason is that 'isPresentationAttribute()' call is heavy and it is detected as a CPU hotspot by the Intel VTune Amplifier profiler.

After this patch is applied the result median time values improve approximately by 2% for the 'modify-element-classname.html' test and by 11% for the 'modify-element-id.html' test (Linux desktop x64).

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196669

[Mikhail, 2015-06-05 12:32:52]

mikhail.pozdnyakov@intel.com changed reviewers:
+ mkwst@chromium.org, sigbjornf@opera.com

[Mikhail, 2015-06-05 12:34:36]

PTAL

[Mike West, 2015-06-07 13:59:44]

LGTM!

https://codereview.chromium.org/1169633002/diff/1/Source/core/dom/Element.cpp
File Source/core/dom/Element.cpp (right):

https://codereview.chromium.org/1169633002/diff/1/Source/core/dom/Element.cpp...
Source/core/dom/Element.cpp:1118: bool testShouldInvalidateStyle =
inActiveDocument() && styleResolver && styleChangeType() < SubtreeStyleChange;
Nit: You can fold this into the `if` on the next line.

[sof, 2015-06-07 19:01:15]

lgtm.

isPresentationAttribute() also shows up in profiles for blink_perf.bindings
tests, iirc.

https://codereview.chromium.org/1169633002/diff/1/Source/core/dom/Element.cpp
File Source/core/dom/Element.cpp (right):

https://codereview.chromium.org/1169633002/diff/1/Source/core/dom/Element.cpp...
Source/core/dom/Element.cpp:1118: bool testShouldInvalidateStyle =
inActiveDocument() && styleResolver && styleChangeType() < SubtreeStyleChange;
On 2015/06/07 13:59:43, Mike West wrote:
> Nit: You can fold this into the `if` on the next line.

Or give it a better name :)

[Mikhail, 2015-06-08 07:17:25]

The CQ bit was checked by mikhail.pozdnyakov@intel.com

[Mikhail, 2015-06-08 07:17:25]

The patchset sent to the CQ was uploaded after l-g-t-m from sigbjornf@opera.com,
mkwst@chromium.org
Link to the patchset: https://codereview.chromium.org/1169633002/#ps20001
(title: "Removed unneeded local var")

[commit-bot: I haz the power, 2015-06-08 07:17:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1169633002/20001

[commit-bot: I haz the power, 2015-06-08 09:18:48]

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

[commit-bot: I haz the power, 2015-06-08 09:18:50]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/65616)

[Mikhail, 2015-06-08 11:19:01]

The CQ bit was checked by mikhail.pozdnyakov@intel.com

[commit-bot: I haz the power, 2015-06-08 11:19:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1169633002/20001

[commit-bot: I haz the power, 2015-06-08 12:25:53]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196669