Enhance chrome.app.window API for shelf integration with pinning support (cont.)

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 33fb35844e4a118d0473ab641e12297547a193b2..246c9cd761c7aec403c694d7e19eccedcbed060d 100644
--- a/ash/shelf/shelf_view_unittest.cc
+++ b/ash/shelf/shelf_view_unittest.cc
@@ -270,6 +270,10 @@ class TestShelfDelegateForShelfView : public ShelfDelegate {
     return app_id_;
   }
 
+  const std::string& GetLaunchIDForShelfID(ShelfID id) override {
+    return base::EmptyString();
+  }
+
   void PinAppWithID(const std::string& app_id) override { NOTREACHED(); }
 
   bool IsAppPinned(const std::string& app_id) override {