mash: Preliminary support for shelf auto-hide

ash/shelf/shelf_layout_manager_observer.h

Index: ash/shelf/shelf_layout_manager_observer.h
diff --git a/ash/shelf/shelf_layout_manager_observer.h b/ash/shelf/shelf_layout_manager_observer.h
index bfb3005dfddc3bc8c488c58295264d788761d493..86b3ce15fe24fb64634cd53a4dcb72474fcc7e8e 100644
--- a/ash/shelf/shelf_layout_manager_observer.h
+++ b/ash/shelf/shelf_layout_manager_observer.h
@@ -15,6 +15,8 @@ class Window;
 
 namespace ash {
 
+class ShelfLayoutManager;
+
 class ASH_EXPORT ShelfLayoutManagerObserver {
  public:
   virtual ~ShelfLayoutManagerObserver() {}
@@ -25,8 +27,13 @@ class ASH_EXPORT ShelfLayoutManagerObserver {
   // Called when the visibility change is scheduled.
   virtual void WillChangeVisibilityState(ShelfVisibilityState new_state) {}
 
+  // Called when the visibility change is committed.
+  virtual void DidChangeVisibilityState(ShelfLayoutManager* layout_manager,

[msw, 2016/05/24 20:46:55]

optional nit: pass the ash::Shelf instead? ditto below.

[James Cook, 2016/05/25 00:25:43]

I moved this method to the delegate and removed the ShelfLayoutManager parameter
below.

+                                        ShelfVisibilityState new_state) {}
+
   // Called when the auto hide state is changed.
-  virtual void OnAutoHideStateChanged(ShelfAutoHideState new_state) {}
+  virtual void OnAutoHideStateChanged(ShelfLayoutManager* layout_manager,
+                                      ShelfAutoHideState new_state) {}
 
   // Called when shelf background animation is started.
   virtual void OnBackgroundUpdated(wm::ShelfBackgroundType background_type,