Stack overflow in CSS parser caused by recursive stylesheet import

Stack overflow in CSS parser caused by recursive stylesheet import
https://bugs.webkit.org/show_bug.cgi?id=83545

Patch by David Barr <davidbarr@chromium.org> on 2012-04-16
Reviewed by Ryosuke Niwa.

Source/WebCore:

Test: http/tests/css/css-imports-redirect-cycle.html

* css/CSSImportRule.cpp:
(WebCore::StyleRuleImport::requestStyleSheet):

LayoutTests:

* http/tests/css/css-imports-redirect-cycle-expected.txt: Added.
* http/tests/css/css-imports-redirect-cycle.css: Added.
* http/tests/css/css-imports-redirect-cycle.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114350 268f45cc-cd09-0410-ab3c-d52691b4dbfc