mash: Preliminary support for shelf auto-hide

ash/test/test_shelf_delegate.cc

Index: ash/test/test_shelf_delegate.cc
diff --git a/ash/test/test_shelf_delegate.cc b/ash/test/test_shelf_delegate.cc
index eda31b584223f8414a131f5d9858c4ecf8afb771..845c67759c017c5337ee6c394a034d40a6426c18 100644
--- a/ash/test/test_shelf_delegate.cc
+++ b/ash/test/test_shelf_delegate.cc
@@ -99,6 +99,10 @@ void TestShelfDelegate::OnShelfAlignmentChanged(Shelf* shelf) {}
 
 void TestShelfDelegate::OnShelfAutoHideBehaviorChanged(Shelf* shelf) {}
 
+void TestShelfDelegate::OnShelfAutoHideStateChanged(Shelf* shelf) {}
+
+void TestShelfDelegate::OnShelfVisibilityStateChanged(Shelf* shelf) {}
+
 ShelfID TestShelfDelegate::GetShelfIDForAppID(const std::string& app_id) {
   for (auto const& iter : shelf_id_to_app_id_map_) {
     if (iter.second == app_id)