Wires up shelf to panel and dock layoutmanagers

mash/wm/shelf_layout_manager.h

Index: mash/wm/shelf_layout_manager.h
diff --git a/mash/wm/shelf_layout_manager.h b/mash/wm/shelf_layout_manager.h
index ae7266c1064c81c9761feeee3afb40ff4752eeea..39be5686258208a96ba1ee95fd6f02b7c5cde06e 100644
--- a/mash/wm/shelf_layout_manager.h
+++ b/mash/wm/shelf_layout_manager.h
@@ -12,10 +12,12 @@
 namespace mash {
 namespace wm {
 
+class ShelfLayoutManagerDelegate;
+
 // Lays out the shelf within shelf containers.
 class ShelfLayoutManager : public LayoutManager {
  public:
-  explicit ShelfLayoutManager(mus::Window* owner);
+  ShelfLayoutManager(mus::Window* owner, ShelfLayoutManagerDelegate* delegate);
   ~ShelfLayoutManager() override;
 
   // Returns the shelf, which may be null.
@@ -32,7 +34,9 @@ class ShelfLayoutManager : public LayoutManager {
  private:
   // Overridden from LayoutManager:
   void LayoutWindow(mus::Window* window) override;
+  void WindowAdded(mus::Window* window) override;
 
+  ShelfLayoutManagerDelegate* delegate_;
   shelf::mojom::Alignment alignment_;
   shelf::mojom::AutoHideBehavior auto_hide_behavior_;