GitLab

Add wildcard string matcher to previews. This would be used for
matching URL (aka page) patterns provided by the hints optimization
server.

Also, fix some existing errors in gn files.

Change-Id: Id24365b8f475b5740b0d897d9514dd1d6d3281d4
Bug: 870039
Reviewed-on: https://chromium-review.googlesource.com/1172159
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582683}