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 f0c43dbf97a0fa8ceb73c279dff119ca40047f86..83f810297aa8512f3d9f40aa7992dca78d265490 100644
--- a/ui/app_list/app_list_view_delegate.h
+++ b/ui/app_list/app_list_view_delegate.h
@@ -149,6 +149,9 @@ class APP_LIST_EXPORT AppListViewDelegate {
   // Returns the list of users (for AppListMenu).
   virtual const Users& GetUsers() const = 0;
 
+  // Returns true if the app list should be centered and in landscape mode.
+  virtual bool ShouldCenterWindow() const = 0;
+
   // Adds/removes an observer for profile changes.
   virtual void AddObserver(AppListViewDelegateObserver* observer) {}
   virtual void RemoveObserver(AppListViewDelegateObserver* observer) {}