Currently, in order to enable scrolling from the shelf to change AppList states, we resolve scroll events into offsets and types, then send over mojo IPC to the AppListView.

This is propogating to other parts of AppListView (AppsGridView::OnScrollEvent) and we should remember to go back to processing events once we can do it from all sources.


When we merge AppList into the ash process, we will no longer need to resolve scroll events, and we can get rid of AppListView::HandleScroll, and AppsGridView::HandleScroll.