Invalid CSS Selector for Content Blockers invalidates others

Invalid CSS Selector for Content Blockers invalidates others
https://bugs.webkit.org/show_bug.cgi?id=148446
rdar://problem/22918235

Reviewed by Benjamin Poulain.

Source/WebCore:

Test: http/tests/contentextensions/invalid-selector.html

* contentextensions/ContentExtensionParser.cpp:
(WebCore::ContentExtensions::loadTrigger):
(WebCore::ContentExtensions::isValidSelector):
(WebCore::ContentExtensions::loadAction):
(WebCore::ContentExtensions::loadRule):
Add a check to see if a selector is valid before adding it.

LayoutTests:

* http/tests/contentextensions/invalid-selector-expected.txt: Added.
* http/tests/contentextensions/invalid-selector.html: Added.
* http/tests/contentextensions/invalid-selector.html.json: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@190602 268f45cc-cd09-0410-ab3c-d52691b4dbfc