mash: Move ownership of ShelfDelegate to WmShell

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 85f9901914af0e7b4b852d2cc6c7c4de73c46d33..23c849be76d7a5b9e1251dce640ddb4c97112574 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -121,7 +121,6 @@ class ScreenPinningController;
 class ScreenPositionController;
 class SessionStateDelegate;
 class Shelf;
-class ShelfDelegate;
 class ShelfWindowWatcher;
 class ShellDelegate;
 struct ShellInitParams;
@@ -449,9 +448,6 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
 
   WindowPositioner* window_positioner() { return window_positioner_.get(); }
 
-  // Returns the launcher delegate, creating if necesary.
-  ShelfDelegate* GetShelfDelegate();
-
   UserMetricsRecorder* metrics() { return user_metrics_recorder_.get(); }
 
   void SetTouchHudProjectionEnabled(bool enabled);
@@ -555,7 +551,6 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
   std::unique_ptr<SessionStateDelegate> session_state_delegate_;
   std::unique_ptr<NewWindowDelegate> new_window_delegate_;
   std::unique_ptr<PointerWatcherDelegate> pointer_watcher_delegate_;
-  std::unique_ptr<ShelfDelegate> shelf_delegate_;
   std::unique_ptr<ShelfWindowWatcher> shelf_window_watcher_;
   std::unique_ptr<WindowPositioner> window_positioner_;