Add a runtime flag for <input type=date>

Add a runtime flag for <input type=date>
https://bugs.webkit.org/show_bug.cgi?id=83853

Reviewed by Adam Barth.

Source/WebCore:

* bindings/generic/RuntimeEnabledFeatures.cpp:
* bindings/generic/RuntimeEnabledFeatures.h:
(WebCore::RuntimeEnabledFeatures::inputTypeDateEnabled): Added.
(WebCore::RuntimeEnabledFeatures::setInputTypeDateEnabled): Added.
* html/InputType.cpp:
(WebCore::createInputTypeFactoryMap):
Don't register type=date if !RuntimeEnabledFeatures::inputTypeDateEnabled()

Source/WebKit/chromium:

* public/WebRuntimeFeatures.h:
(WebRuntimeFeatures): Add enableInputTypeDate() and isInputTypeDateEnabled().
* src/WebRuntimeFeatures.cpp:
(WebKit::WebRuntimeFeatures::enableInputTypeDate): Added.
(WebKit::WebRuntimeFeatures::isInputTypeDateEnabled): Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114101 268f45cc-cd09-0410-ab3c-d52691b4dbfc