[CSS Regions] Add performance tests for selection with mixed content
https://bugs.webkit.org/show_bug.cgi?id=126427

Reviewed by Ryosuke Niwa.

Add new performance tests for selection in CSS Regions mixing regular
content with regions. 2 new tests are added, one checking select all
command and another simulating a user selection passing through all the
paragraphs (similar to Layout/RegionsSelection.html).

Test are skipped for now while implementation of selection in CSS
Regions is still evolving.

* Layout/RegionsExtendingSelectionMixedContent.html: Added.
* Layout/RegionsSelectAllMixedContent.html: Added.
* Layout/resources/regions.css:
(.regular):
* Layout/resources/regions.js:
* Skipped:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162065 268f45cc-cd09-0410-ab3c-d52691b4dbfc
6 files changed