Let gn check verify that blink/public dependencies are sane

We can't have gn check look through all of blink because it's
a messy monolithic pile of internal dependencies, but the
public API layer has strict rules that should be enforced by
gn check.

Also removing a mojo header from a build target since it's supposedly
already in a mojo build target and listing it here as well
makes gn check unhappy.

Bug: 898837
Change-Id: Id46485ffa4ffeb0c897f6d22e684f6d45d4804e6
Reviewed-on: https://chromium-review.googlesource.com/c/1307373
Commit-Queue: Daniel Bratell <bratell@opera.com>
Reviewed-by: Scott Graham <scottmg@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607283}
2 files changed