Remove two unnecessary mallocs from the main-thread-parser code path
https://bugs.webkit.org/show_bug.cgi?id=111249

Reviewed by Adam Barth.

I noticed these while fixing up our Vector -> String conversions
but never went back to fix the FIXME.

AtomicString(Vector<UChar, capacity>) is smart enough to avoid mallocing
if the represented string is already in the AtomicString table.  It
also handles 8bit vs. 16bit and empty() just like nameString() does.

I also removed a 3rd caller to nameString() in the XSSAuditor which
was causing an unnecessary malloc in both the main and background
thread parser paths.

* html/parser/AtomicHTMLToken.h:
(WebCore::AtomicHTMLToken::AtomicHTMLToken):
* html/parser/HTMLToken.h:
* html/parser/XSSAuditor.cpp:
(WebCore):
(WebCore::threadSafeMatch):
(WebCore::hasName):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144544 268f45cc-cd09-0410-ab3c-d52691b4dbfc