Reviewed by Darin Adler.

        Replace getAttribute().isNull() with fastHasAttribute()
        https://bugs.webkit.org/show_bug.cgi?id=50719

        Covered by existing tests.

        * dom/SelectElement.cpp:
        (WebCore::SelectElement::reset):
        * html/HTMLAppletElement.cpp:
        (WebCore::HTMLAppletElement::rendererIsNeeded):
        * html/HTMLCollection.cpp:
        (WebCore::HTMLCollection::itemAfter):
        * html/HTMLFormControlElement.cpp:
        (WebCore::HTMLFormControlElement::formNoValidate):
        * html/HTMLFormElement.cpp:
        (WebCore::HTMLFormElement::noValidate):
        * html/HTMLInputElement.cpp:
        (WebCore::HTMLInputElement::defaultChecked):
        (WebCore::HTMLInputElement::multiple):
        (WebCore::HTMLInputElement::webkitdirectory):
        * html/HTMLOptionElement.cpp:
        (WebCore::HTMLOptionElement::defaultSelected):
        * html/HTMLScriptElement.cpp:
        (WebCore::HTMLScriptElement::asyncAttributeValue):
        (WebCore::HTMLScriptElement::deferAttributeValue):
        * rendering/RenderFileUploadControl.cpp:
        (WebCore::RenderFileUploadControl::allowsMultipleFiles):
        (WebCore::RenderFileUploadControl::allowsDirectoryUpload):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@73589 268f45cc-cd09-0410-ab3c-d52691b4dbfc