GitLab

A new test was added to the legacy_input_router_impl_unittest but wasn't
cloned over to the new input_router_impl. Add the missing code.

BUG=727866

Change-Id: Id7df047f173be06e4447d9ff99c383b85f2e3fed
Reviewed-on: https://chromium-review.googlesource.com/598545
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491793}