mash: Preliminary support for shelf auto-hide

ash/shelf/shelf_view_unittest.cc

Index: ash/shelf/shelf_view_unittest.cc
diff --git a/ash/shelf/shelf_view_unittest.cc b/ash/shelf/shelf_view_unittest.cc
index a2a083e4d12aa783f46446af33bf6bbbc3b942c9..6e797ad86173c501da96eea6908967d75101bc00 100644
--- a/ash/shelf/shelf_view_unittest.cc
+++ b/ash/shelf/shelf_view_unittest.cc
@@ -255,6 +255,10 @@ class TestShelfDelegateForShelfView : public ShelfDelegate {
 
   void OnShelfAutoHideBehaviorChanged(Shelf* shelf) override {}
 
+  void OnShelfAutoHideStateChanged(Shelf* shelf) override {}
+
+  void OnShelfVisibilityStateChanged(Shelf* shelf) override {}
+
   ShelfID GetShelfIDForAppID(const std::string& app_id) override {
     ShelfID id = 0;
     EXPECT_TRUE(base::StringToInt(app_id, &id));