[CSSOM] Extraneous whitespace in CSSImportRule.cssText

https://bugs.webkit.org/show_bug.cgi?id=100657

Patch by Glenn Adams <glenn@skynav.com> on 2012-10-29
Reviewed by Simon Fraser.

Source/WebCore:

Remove extraneous whitespace when serializing CSSImportRule.cssText when
media list is empty.

Test: cssom/cssimportrule-media.html

* css/CSSImportRule.cpp:
(WebCore::CSSImportRule::cssText):
Don't append extra whitespace if mediaText is empty.

LayoutTests:

Test (from CSS WG) that checks serializion of CSSImportRule.cssText.

* http/tests/css/shared-stylesheet-mutation-expected.txt:
* http/tests/css/shared-stylesheet-mutation-preconstruct-expected.txt:
Fix expected output to match removal of extraneous space.

* cssom/cssimportrule-media-expected.txt: Added.
* cssom/cssimportrule-media.html: Added.
* cssom/resources/import.css: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@132834 268f45cc-cd09-0410-ab3c-d52691b4dbfc