[Merge m59] Only whitelist messages.json files in _locales for content verification

[Merge m59] Only whitelist messages.json files in _locales for content verification

The messages.json files used for i18n/l10n get transcoded during the
extension install process, so we need to avoid doing content
verification checks on them because we expect their contents to be
modified. The code we had for testing whether a path should be skipped
because of this was incorrect, skipping more files than it should.

Through the courtesy of Antony: https://crrev.com/2572833004

The CL also renames some path variables in content verification
code to stress that they contain unix style '/' separators.

BUG=672008
Review-Url: https://codereview.chromium.org/2834873002
Cr-Commit-Position: refs/heads/master@{#466769}
(cherry picked from commit d05d1e844e7d376400a7437989c4c50a5875b36f)

Review-Url: https://codereview.chromium.org/2845223003 .
Cr-Commit-Position: refs/branch-heads/3071@{#302}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/503cfcd789d2d9769c2e1a6a1fe53b7be00c59ce

[lazyboy, 2017-04-28 20:40:48]

Description was changed from

==========
[Merge m59] Only whitelist messages.json files in _locales for content
verification

The messages.json files used for i18n/l10n get transcoded during the
extension install process, so we need to avoid doing content
verification checks on them because we expect their contents to be
modified. The code we had for testing whether a path should be skipped
because of this was incorrect, skipping more files than it should.

Through the courtesy of Antony: https://crrev.com/2572833004

The CL also renames some path variables in content verification
code to stress that they contain unix style '/' separators.

BUG=672008

Review-Url: https://codereview.chromium.org/2834873002
Cr-Commit-Position: refs/heads/master@{#466769}
(cherry picked from commit d05d1e844e7d376400a7437989c4c50a5875b36f)
==========

to

==========
[Merge m59] Only whitelist messages.json files in _locales for content
verification

The messages.json files used for i18n/l10n get transcoded during the
extension install process, so we need to avoid doing content
verification checks on them because we expect their contents to be
modified. The code we had for testing whether a path should be skipped
because of this was incorrect, skipping more files than it should.

Through the courtesy of Antony: https://crrev.com/2572833004

The CL also renames some path variables in content verification
code to stress that they contain unix style '/' separators.

BUG=672008

Review-Url: https://codereview.chromium.org/2834873002
Cr-Commit-Position: refs/heads/master@{#466769}
(cherry picked from commit d05d1e844e7d376400a7437989c4c50a5875b36f)

Review-Url: https://codereview.chromium.org/2845223003 .
Cr-Commit-Position: refs/branch-heads/3071@{#302}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/503cfcd789d2d9769c2e1a6a1fe5...
==========

[lazyboy, 2017-04-28 20:40:50]

Committed patchset #1 (id:1) manually as
503cfcd789d2d9769c2e1a6a1fe53b7be00c59ce.