XSLT-created HTML documents do not inherit first party for cookies from originally...

XSLT-created HTML documents do not inherit first party for cookies from originally loaded XML.
https://bugs.webkit.org/show_bug.cgi?id=74757

Reviewed by Alexey Proskuryakov.

Source/WebCore:

Tests: http/tests/security/cookies/first-party-cookie-allow-xslt.xml
       http/tests/security/cookies/third-party-cookie-blocking-xslt.xml

* xml/XSLTProcessor.cpp:
(WebCore::XSLTProcessor::createDocumentFromSource):

LayoutTests:

* http/tests/security/cookies/first-party-cookie-allow-xslt-expected.txt: Added.
* http/tests/security/cookies/first-party-cookie-allow-xslt.xml: Added.
* http/tests/security/cookies/resources/first-party-cookie-allow.xsl: Added.
* http/tests/security/cookies/resources/third-party-cookie-blocking.xsl: Added.
* http/tests/security/cookies/third-party-cookie-blocking-xslt-expected.txt: Added.
* http/tests/security/cookies/third-party-cookie-blocking-xslt.xml: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@103511 268f45cc-cd09-0410-ab3c-d52691b4dbfc