mash: Merge ChromeLauncherController and *Impl subclass.

Combine the base class and only remaining subclass. Simplify:
-Remove some unnecessary accessors for the subclass.
-Merge constructors, destructors, Init/OnInit, OnAppImageUpdated.
-Make some CLC base classes and functions private.
-Remove unused includes.

Rename test files and classes.

BUG=557406
TEST=No functional changes; refactoring only.
R=jamescook@chromium.org

Review-Url: https://codereview.chromium.org/2839933005
Cr-Commit-Position: refs/heads/master@{#467557}
36 files changed