Abstracts the logic for restoration into the built-in teardown()
handler.
Also purify the test configuration by setting wgHooks and
wgFileExtensions to otherwise empty arrays instead of extending
existing ones.
Change-Id: Ied65ee62f658dd650c603a54e72cd19965867a8f
* Filter <style> elements
* Normalize style elements and attributes before filtering
* Add checks for attributes that contain css
* Add unit tests for html5sec and reported bugs
Bug:69008
Change-Id: I732eece710f1bfaaeea1e5de541fcd4cfb375de7
