mash: Use ChromeLauncherControllerImpl, remove Mus subclass stub.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
index aa8703479dacc8e3d9e91014d255744b33d542b7..c994378f797ed331f71582214910f5038ab0cfd0 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h
@@ -104,6 +104,8 @@ class ChromeLauncherControllerImpl
   const std::string& GetLaunchIDForShelfID(ash::ShelfID id) override;
   void AttachProfile(Profile* profile_to_attach) override;
 
+  ash::ShelfModel* shelf_model() const { return model_; }

[James Cook, 2017/04/26 01:03:26]

Why not provide a GetShelfModel() on ChromeLauncherController instead? Then
there would be the possibility of returning a fake/stub one in unit tests.

It feels kinda of weird to have a relatively nice abstract base class (CLC) then
tie all the other classes to the concrete CLCImpl.

Is your long-term plan to collapse CLC and CLCImpl? Am I missing something?

[msw, 2017/04/26 01:35:14]

Yes, I plan to merge CLC and CLCImpl in an imminent followup CL. I thought this
might be easier, otherwise I'd have to go back and switch GetShelfModel() to
shelf_model() at all these call sites anyway.

+
   // Access to the BrowserStatusMonitor for tests.
   BrowserStatusMonitor* browser_status_monitor_for_test() {
     return browser_status_monitor_.get();