GitLab

Repurpose spell checking code that was testing for the mojo channel
to common code. Write a test that causes the showGuessPanel selector
to be sent and verify the panel is requested to be shown.

BUG=782836

Change-Id: I9d8ac59ac3bf96bbcd7e538f794eac71e0bc7553
Reviewed-on: https://chromium-review.googlesource.com/786260
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Rachel Blum <groby@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522088}