Don't use threaded HTML parser for data: URLs
https://bugs.webkit.org/show_bug.cgi?id=108096

Reviewed by Eric Seidel.

data: URLs are currently loaded synchronously. Using the main thread parser for them preserves this behavior.
This fixes fast/dom/HTMLDocument/document-open-return-value.html and probably others.

No new tests because covered by existing tests.

* html/parser/HTMLParserOptions.cpp:
(WebCore::HTMLParserOptions::HTMLParserOptions):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140992 268f45cc-cd09-0410-ab3c-d52691b4dbfc