GitLab

Create the basic MVC components for the contextual suggestions component
and content sub-component. Sets up basic connection to the bottom sheet
and moves some prototype code to the ContextualSuggestionsMediator.

A follow-up CL will remove the old, dead prototype code.

BUG=822842

Change-Id: I01461f5ae4c5ec0cc33dbad31daa1415fe46c2cf
Reviewed-on: https://chromium-review.googlesource.com/967010
Commit-Queue: Theresa <twellington@chromium.org>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544737}