Null-check the page overlay before trying to use it.

Reviewed by Simon Fraser.

* WebProcess/WebPage/mac/TiledCoreAnimationDrawingArea.mm:
(WebKit::TiledCoreAnimationDrawingArea::scroll):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145096 268f45cc-cd09-0410-ab3c-d52691b4dbfc
        FormData should allow setting filename to empty
        https://bugs.webkit.org/show_bug.cgi?id=111687

        Reviewed by Brady Eidson.

        Tests: http/tests/local/formdata/send-form-data-with-empty-blob-filename.html
               http/tests/local/formdata/send-form-data-with-empty-file-filename.html

        * html/FileInputType.cpp: (WebCore::FileInputType::appendFormData):
        Use a Blob for empty file input, not a hacky File with empty path.

        * platform/network/FormData.cpp: (WebCore::FormData::appendKeyValuePairItems):
        Missing value is a null string. If the string is empty, we should treat is as
        authoritative.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145097 268f45cc-cd09-0410-ab3c-d52691b4dbfc