Add NetworkNotificationView to tray_network.

ash/system/tray/system_tray.h

Index: ash/system/tray/system_tray.h
diff --git a/ash/system/tray/system_tray.h b/ash/system/tray/system_tray.h
index 51258d38629240fc5604414b8a5681149e7c0a06..873b40336137ffcb67e6f58c69844d36b98de696 100644
--- a/ash/system/tray/system_tray.h
+++ b/ash/system/tray/system_tray.h
@@ -160,6 +160,9 @@ class ASH_EXPORT SystemTray : public internal::ActionableView,
   friend class internal::SystemTrayLayerAnimationObserver;
   friend class internal::SystemTrayBubble;
 
+  // Resets |bubble_| and clears any related state.
+  void DestroyBubble();
+
   // Called when the widget associated with |bubble| closes. |bubble| should
   // always == |bubble_|. This triggers destroying |bubble_| and hiding the
   // launcher if necessary.
@@ -253,6 +256,10 @@ class ASH_EXPORT SystemTray : public internal::ActionableView,
   scoped_ptr<internal::SystemTrayLayerAnimationObserver>
       layer_animation_observer_;
 
+  // Keep track of the default view height so that when we create detailed
+  // views directly (e.g. from a notification) we know what height to use.
+  int default_bubble_height_;
+
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };