Reviewed by Adele.

    Reviewed by Adele.

        - fixed <rdar://problem/4025618> Crash while searching at hollywoodvideo.com

        * khtml/html/html_formimpl.h: Added valueWithDefault.
        * khtml/html/html_formimpl.cpp:
        (DOM::HTMLInputElementImpl::appendFormData): Call valueWithDefault instead of going at the render object
        to try to get the default value; there may be no render object if this is display:none.
        (DOM::HTMLInputElementImpl::valueWithDefault): Added. Knows about the defaults for "submit" and "reset"
        buttons; otherwise just returns the value as-is.

        * khtml/rendering/render_form.h: Removed the defaultLabel member functions.
        * khtml/rendering/render_form.cpp:
        (RenderSubmitButton::rawText): Call valueWithDefault instead of using defaultLabel function here on
        the render side. The DOM needs to know how to deal with the default anyway for form submission.
        (RenderSubmitButton::defaultLabel): Removed.
        (RenderResetButton::defaultLabel): Removed.
        (RenderPushButton::defaultLabel): Removed.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8713 268f45cc-cd09-0410-ab3c-d52691b4dbfc