Simplify form validation handling

Simplify form validation handling

This CL contains some part of https://codereview.chromium.org/460343004/ by
sudarshan.p, which was reverted by a performance regression.

This CL simplifies form validation state handling code by
 - lazy update of m_isValid
   setNeedsValidityCheck just makes m_isValid dirty.
 - m_isValid takes care of willValidate state too.
   m_isValid = !willValidate() || valid()

We switched to invalidation sets for :valid and :invalid by Blink
r184392. Calling pseudoStateChanged() for unchanged validity state won't have so
bad performance. So, we can evaluate m_isValid lazily.
This CL fixes a SELECT default selection bug, crbug.com/461586, because
We don't call HTMLSelectElement::selectedIndex() during SELECT children
parsing.

We need to change the meaning of m_isValid slightly so that it takes care of
willValidate(). This is necessary to clean m_validityIsDirty of associated
controls in HTMLFormElement::checkInvalidControlsAndCollectUnhandled.
Without this change, there would be a case where willValidate state
change won't invalidate :valid :invalid style of <form>.

This CL will have a few percent regression on blink_perf.dom:textarea-edit.
A fix for the performance regression will be landed soon.

BUG=461586
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=190795

[tkent, 2015-02-23 06:16:41]

Patchset #1 (id:1) has been deleted

[tkent, 2015-02-23 06:17:07]

tkent@chromium.org changed reviewers:
+ keishi@chromium.org

[tkent, 2015-02-23 06:17:07]

Keishi, would you review this please?

[tkent, 2015-02-23 06:43:17]

+sudarshan.p

[keishi, 2015-02-24 08:03:32]

lgtm

[tkent, 2015-02-24 08:10:18]

The CQ bit was checked by tkent@chromium.org

[commit-bot: I haz the power, 2015-02-24 08:11:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/943303002/20001

[commit-bot: I haz the power, 2015-02-24 08:28:29]

Committed patchset #1 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=190723

[hiroshige, 2015-02-24 11:27:03]

A revert of this CL (patchset #1 id:20001) has been created in
https://codereview.chromium.org/948373002/ by hiroshige@chromium.org.

The reason for reverting is: This CL breaks browser test:
AllForms_FormStructureBrowserTest.DataDrivenHeuristics_108

http://build.chromium.org/p/chromium.webkit/builders/Mac10.8%20Tests/builds/1...
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/42755
http://build.chromium.org/p/chromium.webkit/builders/Linux%20ChromiumOS%20Tes...
http://build.chromium.org/p/chromium.webkit/builders/Linux%20ChromiumOS%20Tes...

Bisected locally on Linux:
./out/Release/browser_tests 
--gtest_filter=AllForms/FormStructureBrowserTest.DataDrivenHeuristics/108

Blink 190722 / Chromium 317759: OK
Blink 190723 / Chromium 317759: NG

So Blink 190723 is reverted..

[tkent, 2015-02-24 23:38:00]

On 2015/02/24 11:27:03, hiroshige wrote:
> A revert of this CL (patchset #1 id:20001) has been created in
> https://codereview.chromium.org/948373002/ by mailto:hiroshige@chromium.org.
> 
> The reason for reverting is: This CL breaks browser test:
> AllForms_FormStructureBrowserTest.DataDrivenHeuristics_108
> 
>
http://build.chromium.org/p/chromium.webkit/builders/Mac10.8%20Tests/builds/1...
>
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/42755
>
http://build.chromium.org/p/chromium.webkit/builders/Linux%20ChromiumOS%20Tes...
>
http://build.chromium.org/p/chromium.webkit/builders/Linux%20ChromiumOS%20Tes...
> 
> Bisected locally on Linux:
> ./out/Release/browser_tests 
> --gtest_filter=AllForms/FormStructureBrowserTest.DataDrivenHeuristics/108
> 
> Blink 190722 / Chromium 317759: OK
> Blink 190723 / Chromium 317759: NG
> 
> So Blink 190723 is reverted..

I investigated the failure, and found the new behavior was correct.
Before this CL,  the following HTML shows [Placeholder] [First].  It's bad.
|required| shouldn't affect the default selection.  With this CL it shows
[First] [First], and both of IE and Firefox show [First] [First].

data:text/html;charset=utf-8,<select required><option value=""
disabled>Placeholder<option>First</select><select><option value=""
disabled>Placeholder<option>First</select>

I'll do:
 - Add a layout test to check it
 - Disable the autofill test
 - Land this
 - Update and enable the autofill test

[tkent, 2015-02-25 03:25:53]

The CQ bit was checked by tkent@chromium.org

[tkent, 2015-02-25 03:25:54]

The patchset sent to the CQ was uploaded after l-g-t-m from keishi@chromium.org
Link to the patchset: https://codereview.chromium.org/943303002/#ps40001 (title:
"add a test")

[commit-bot: I haz the power, 2015-02-25 03:26:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/943303002/40001

[commit-bot: I haz the power, 2015-02-25 03:29:41]

Committed patchset #2 (id:40001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=190795