https://bugs.webkit.org/show_bug.cgi?id=98228

Reviewed by Kentaro Hara.

Stop copying multiple members of LayoutParameters in DateTimeEditBuilder
constructor. This change improves code size and runtime cost.

No new tests. This doesn't change user-visible behavior.

* html/shadow/DateTimeEditElement.cpp:
(DateTimeEditBuilder): Add a comment about lifetime of objects.
(WebCore::DateTimeEditBuilder::stepRange):
Added. A helper to access m_parameters.stepRange.
(WebCore::DateTimeEditBuilder::DateTimeEditBuilder):
Remove m_stepRange, m_localizer, m_placeholderFor* members.
Add m_parameters.
(WebCore::DateTimeEditBuilder::needMillisecondField):
Use stepRange() instead of m_stepRange.
(WebCore::DateTimeEditBuilder::visitField):
Use m_parameters.placeholderFor*.
(WebCore::DateTimeEditBuilder::shouldMillisecondFieldReadOnly):
Use stepRange() instead of m_stepRange.
(WebCore::DateTimeEditBuilder::shouldMinuteFieldReadOnly): ditto.
(WebCore::DateTimeEditBuilder::shouldSecondFieldReadOnly): ditto.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@130246 268f45cc-cd09-0410-ab3c-d52691b4dbfc