New interface and function for form association

I'm planning on moving all form associated code out of HTMLElementFactory and out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or not.

HTMLConstructionSite is the only place where a form is passed into HTMLElementFactory::createHTMLElement.

BUG=672359
Committed: https://crrev.com/d1277589fc7407df208a562986341c49c298b752
Cr-Commit-Position: refs/heads/master@{#436548}

[yurak, 2016-12-01 06:28:15]

Description was changed from

==========
New interface and function for form association

BUG=
==========

to

==========
I'm planning on moving all form associated code out of HTMLElementFactory.

I created a new interface to be extended by form associated elements which has a
function to hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

BUG=
==========

[yurak, 2016-12-01 06:28:15]

yurak@google.com changed reviewers:
+ tkent@chromium.org

[yurak, 2016-12-01 06:28:56]

Description was changed from

==========
I'm planning on moving all form associated code out of HTMLElementFactory.

I created a new interface to be extended by form associated elements which has a
function to hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

BUG=
==========

to

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

BUG=
==========

[yurak, 2016-12-02 05:47:57]

PTL

[yurak, 2016-12-02 05:55:24]

Description was changed from

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

BUG=
==========

to

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

HTMLConstructionSite is the only place where a form is passed into
HTMLElementFactory::createHTMLElement.

BUG=
==========

[tkent, 2016-12-02 06:00:09]

We already have core/html/FormAssociatedElement.h, which is not an Element
subclass, but an interface.
Can you reuse it for your purpose?

[yurak, 2016-12-02 07:34:40]

On 2016/12/02 at 06:00:09, tkent wrote:
> We already have core/html/FormAssociatedElement.h, which is not an Element
subclass, but an interface.
> Can you reuse it for your purpose?

One of the form associated elements, HTMLImageElement, doesn't inherit from
FormAssociatedElement.

[tkent, 2016-12-02 07:55:53]

On 2016/12/02 at 07:34:40, yurak wrote:
> On 2016/12/02 at 06:00:09, tkent wrote:
> > We already have core/html/FormAssociatedElement.h, which is not an Element
subclass, but an interface.
> > Can you reuse it for your purpose?
> 
> One of the form associated elements, HTMLImageElement, doesn't inherit from
FormAssociatedElement.

Ah, you're right.  Ok, I agree about introducing a common interface of
HMTLImageElement and FormAssociatedElement.
However, having both of FormAssociatedElement and FormAssociated would be very
confusing. So, please rename FormAssociatedElement to ListedElement before
adding your FormAssociated interface.
https://html.spec.whatwg.org/multipage/forms.html#category-listed

Also, adding FormAssociated interface with no classes implementing it doesn't
make much sense. I recommend adding FormAssociated interface and inheriting
HTMLImageElement/ListedElement from FormAssociated in a single CL.

[yurak, 2016-12-05 01:20:38]

Added FormAssociated interface to HTMLImageElement and ListedElement. PTL :)

[tkent, 2016-12-05 01:53:51]

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/html/FormAssociated.h (right):

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/html/FormAssociated.h:12: // Contains code to
associate form with a form associated element
Please add a specification link.
https://html.spec.whatwg.org/multipage/forms.html#form-associated-element

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/html/FormAssociated.h:15: virtual void
setAssociatedForm(HTMLFormElement*) = 0;
The function name sounds like a simple setter for |m_associatedForm|.  I prefer
something like |associateTo()|.

Can the argument be null?  Please add a comment about it.

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/html/HTMLElement.h (right):

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/html/HTMLElement.h:123: virtual FormAssociated*
toFormAssociated() { return nullptr; };
We avoid to add such conversion functions to Element because there are too many
such conversions.
Please
 - Add HTMLElement::isFormAssociated, and HTMLImageElement,
HTMLFormControlElement, and HTMLObjectElement should implement it so that it
returns |true|.
 - Add DEFINE_TYPE_CAST(FormAssociated, HTMLElement, element,
element->isFormAssociated(), element.isFormAssociated()); to FormAssociated.h
 - In HTMLConstructionSite.cpp,
  if (isFormAssociated(element))
    toFormAssociated(element)->setAssociatedForm(form);

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/html/HTMLImageElement.cpp (right):

https://codereview.chromium.org/2537133005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/html/HTMLImageElement.cpp:889: void
HTMLImageElement::setAssociatedForm(HTMLFormElement* form) {
You move the association code to setAssociatedForm() in HTMLImageElement, but
not for HTMLFormControlElement and HTMLObjectElement.  It's inconsistent.

I recommend:
 - Do it for HTMLFormControlElement and HTMLObjectElement too, or
 - Don't add FormAssociated::setAssociatedForm at all in this CL, and introduce
it and update HTMLImageElement, HTMLFormControlElement, and HTMLObjectElement in
a next CL.

[yurak, 2016-12-06 06:56:57]

PTL.

FormAssociated interface added to HTMLImageElement, HTMLObjectElement, and
HTMLFormControlElement.
I'll move the form association code from the constructor to the new function in
a following patch.

[tkent, 2016-12-06 07:00:16]

lgtm

https://codereview.chromium.org/2537133005/diff/100001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/html/FormAssociated.h (right):

https://codereview.chromium.org/2537133005/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/html/FormAssociated.h:1: // Copyright 2016 The
Chromium Authors. All rights reserved.
Please add FormAssociated.h to core/html/BUILD.gn.

[yurak, 2016-12-06 07:35:53]

The CQ bit was checked by yurak@google.com

[yurak, 2016-12-06 07:35:56]

The patchset sent to the CQ was uploaded after l-g-t-m from tkent@chromium.org
Link to the patchset: https://codereview.chromium.org/2537133005/#ps120001
(title: "Added to BUILD.gn")

[commit-bot: I haz the power, 2016-12-06 07:36:05]

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, 2016-12-06 09:14:33]

CQ is committing da patch.

Bot data: {"patchset_id": 120001, "attempt_start_ts": 1481009753320900,
"parent_rev": "b178644c159d45e0cd62663c6afcbd5ce5666c49", "commit_rev":
"ac9dc90695147c775c28c7021f9ede646d9e61a2"}

[commit-bot: I haz the power, 2016-12-06 09:15:01]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2016-12-06 09:16:56]

Description was changed from

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

HTMLConstructionSite is the only place where a form is passed into
HTMLElementFactory::createHTMLElement.

BUG=
==========

to

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

HTMLConstructionSite is the only place where a form is passed into
HTMLElementFactory::createHTMLElement.

BUG=

Committed: https://crrev.com/d1277589fc7407df208a562986341c49c298b752
Cr-Commit-Position: refs/heads/master@{#436548}
==========

[commit-bot: I haz the power, 2016-12-06 09:16:57]

Patchset 7 (id:??) landed as
https://crrev.com/d1277589fc7407df208a562986341c49c298b752
Cr-Commit-Position: refs/heads/master@{#436548}

[yurak, 2016-12-08 03:54:49]

Description was changed from

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

HTMLConstructionSite is the only place where a form is passed into
HTMLElementFactory::createHTMLElement.

BUG=

Committed: https://crrev.com/d1277589fc7407df208a562986341c49c298b752
Cr-Commit-Position: refs/heads/master@{#436548}
==========

to

==========
I'm planning on moving all form associated code out of HTMLElementFactory and
out of the constructors of HTML elements.

New interface to be extended by form associated elements which has a function to
hold all form association code.

New function in HTMLElement.h to check if an HTMLElement is form associated or
not.

HTMLConstructionSite is the only place where a form is passed into
HTMLElementFactory::createHTMLElement.

BUG=672359

Committed: https://crrev.com/d1277589fc7407df208a562986341c49c298b752
Cr-Commit-Position: refs/heads/master@{#436548}
==========