Introduce RadioButtonGroup class to keep track of the group members and required...

Introduce RadioButtonGroup class to keep track of the group members and required state
https://bugs.webkit.org/show_bug.cgi?id=74909

Reviewed by Darin Adler.

Source/WebCore:

RadioButtonGroup contains a set of member radio buttons in the group,
and "required" status of the group. This helps implementing correct
radio button validity, and improving performance of updating validity
status of radio buttons.

This change fixes the following bugs:
- A radio button should be "required" if one of a member of the same
  group has the "required" attribute.
  https://bugs.webkit.org/show_bug.cgi?id=76365
- :invalid style is not applied when a checked radio button is removed
  from its radio group
  https://bugs.webkit.org/show_bug.cgi?id=74914
- Loading a page with N radio buttons in a group takes O(N^2) time.

Tests: fast/forms/radio/radio-live-validation-style.html
       perf/adding-radio-buttons.html

* dom/CheckedRadioButtons.cpp:
(WebCore::RadioButtonGroup::isEmpty):
(WebCore::RadioButtonGroup::isRequired):
(WebCore::RadioButtonGroup::checkedButton):
(WebCore::RadioButtonGroup::RadioButtonGroup):
(WebCore::RadioButtonGroup::create):
(WebCore::RadioButtonGroup::isValid):
(WebCore::RadioButtonGroup::setCheckedButton):
(WebCore::RadioButtonGroup::add):
(WebCore::RadioButtonGroup::updateCheckedState):
(WebCore::RadioButtonGroup::requiredAttributeChanged):
(WebCore::RadioButtonGroup::remove):
(WebCore::RadioButtonGroup::setNeedsValidityCheckForAllButtons):
Add RadioButtonGroup class. It keeps track of pointers to member radio
buttons and required status of the group in addition to the checked
radio button pointer.

(WebCore::CheckedRadioButtons::CheckedRadioButtons):
(WebCore::CheckedRadioButtons::~CheckedRadioButtons):
Define empty constructor and destructor in order to avoid exposing
RadioButtonGroup class.

(WebCore::CheckedRadioButtons::addButton):
(WebCore::CheckedRadioButtons::updateCheckedState):
(WebCore::CheckedRadioButtons::requiredAttributeChanged):
(WebCore::CheckedRadioButtons::checkedButtonForGroup):
(WebCore::CheckedRadioButtons::isInRequiredGroup):
(WebCore::CheckedRadioButtons::removeButton):
Change the HashMap member of this class so that it maps a group name to
a RadioButtonGroup object. These functions just get a RadioButtonGroup
object and call a corresponding member function of RadioButtonGroup.

* dom/CheckedRadioButtons.h: Update declarations.

* html/HTMLFormControlElement.cpp:
(WebCore::HTMLFormControlElement::parseMappedAttribute):
(WebCore::HTMLFormControlElement::requiredAttributeChanged):
Move a part of parseMappedAttribute() into requiredAttributeChanged().
* html/HTMLFormControlElement.h: Add requiredAttributeChanged().
* html/HTMLInputElement.cpp:
(WebCore::HTMLInputElement::valueMissing):
Move required check code to InputType::valueMissing implementations.
RadioInputType needs special handling for checking required state.
readOnly() and disabled() are unnecessary because willValidate() checks them.
(WebCore::HTMLInputElement::setChecked):
Call new function CheckedRadioButtons::updateCheckedState() instead of
removeButton() and updateCheckedRadioButtons().
(WebCore::HTMLInputElement::requiredAttributeChanged):
Override this to call CheckedRadioButtons::requiredAttributeChanged().
* html/HTMLInputElement.h: Add requiredAttributeChanged().
* html/RadioInputType.cpp:
(WebCore::RadioInputType::valueMissing):
Check required state by CheckedRadioButtons::isInRequiredGroup().
* html/RadioInputType.h: Remove attach().

* html/CheckboxInputType.cpp:
(WebCore::CheckboxInputType::valueMissing):
  Move required check from HTMLInputElement::valueMissing().
* html/FileInputType.cpp:
(WebCore::FileInputType::valueMissing): ditto.
* html/TextFieldInputType.cpp:
(WebCore::TextFieldInputType::valueMissing): ditto.

LayoutTests:

* fast/forms/radio/radio-live-validation-style-expected.txt: Added.
* fast/forms/radio/radio-live-validation-style.html: Added.

* fast/forms/script-tests/ValidityState-valueMissing-radio.js:
- Update the expectation for the behavior change of
  https://bugs.webkit.org/show_bug.cgi?id=76365
- Add test cases for radio buttons not in a radio button group.
* fast/forms/ValidityState-valueMissing-radio-expected.txt: ditto.

* perf/adding-radio-buttons-expected.txt: Added.
* perf/adding-radio-buttons.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105710 268f45cc-cd09-0410-ab3c-d52691b4dbfc