Send Navigation notifications to clients.

mash/webtest/webtest.cc

Index: mash/webtest/webtest.cc
diff --git a/mash/webtest/webtest.cc b/mash/webtest/webtest.cc
index c78e9a074ed3606d41f90e2dc5611741288754b4..0a0700eea0e2e4c02e495bb96e5f92ce1eae7d60 100644
--- a/mash/webtest/webtest.cc
+++ b/mash/webtest/webtest.cc
@@ -123,6 +123,14 @@ class UI : public views::WidgetDelegateView,
   void Close() override {
     GetWidget()->Close();
   }
+  void NavigationPending(navigation::mojom::NavigationEntryPtr entry) override {
+  }
+  void NavigationCommitted(
+      navigation::mojom::NavigationCommittedDetailsPtr details,
+      int current_index) override {}
+  void NavigationEntryChanged(navigation::mojom::NavigationEntryPtr entry,
+                              int entry_index) override {}
+  void NavigationListPruned(bool from_front, int count) override {}
 
   Webtest* webtest_;
   mus::Window* content_area_ = nullptr;