GitLab

This CL
  - Introduces url_pattern_index::kUrlPatternIndexFormatVersion to keep a track
    of the current format version of the UrlPatternIndex schema.
  - Adds checks to url_pattern_index clients (Declarative net request and
    subresource_filter) to ensure that their ruleset format versions are updated
    whenever kUrlPatternIndexFormatVersion is changed.
  - Adds presubmit checks to components/url_pattern_index to ensure that
    kUrlPatternIndexFormatVersion is kept updated.

BUG=877214, 755717

Change-Id: Ib82b775e3da2112d5f17a2040ec495a7ff8e18d9
Reviewed-on: https://chromium-review.googlesource.com/1187706
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586098}