Use centered app list position whenever virtual keyboard is enabled.

ui/app_list/app_list_view_delegate.h

Index: ui/app_list/app_list_view_delegate.h
diff --git a/ui/app_list/app_list_view_delegate.h b/ui/app_list/app_list_view_delegate.h
index df7fcf8575404be4d7a461029cce16c1af22b6d4..1e8dbff703dab4ea9b5003ec06faeb1466850963 100644
--- a/ui/app_list/app_list_view_delegate.h
+++ b/ui/app_list/app_list_view_delegate.h
@@ -150,6 +150,10 @@ class APP_LIST_EXPORT AppListViewDelegate {
   // Returns the list of users (for AppListMenu).
   virtual const Users& GetUsers() const = 0;
 
+  // Returns true if the experimental app list position should be used.
+  // (Centered, and wide instead of tall.)
+  virtual bool UseExperimentalAppListPosition() const = 0;
+
   // Returns the bounds of the virtual keyboard if it is currently visible.
   // Returns an empty rect if it is not visible.
   virtual gfx::Rect GetVirtualKeyboardBounds() const = 0;