Created NavigationManager::CopyStateFromAndPrune().

ios/web/public/test/fakes/test_navigation_manager.mm

Index: ios/web/public/test/fakes/test_navigation_manager.mm
diff --git a/ios/web/public/test/fakes/test_navigation_manager.mm b/ios/web/public/test/fakes/test_navigation_manager.mm
index 579a1e791dd7d686a614de38ec05555d3b99470d..49cbc3b984ae419b0a460b60a6ee83a146ae17d1 100644
--- a/ios/web/public/test/fakes/test_navigation_manager.mm
+++ b/ios/web/public/test/fakes/test_navigation_manager.mm
@@ -150,6 +150,16 @@
   return NavigationItemList();
 }
 
+void TestNavigationManager::CopyStateFromAndPrune(
+    const NavigationManager* source) {
+  NOTREACHED();
+}
+
+bool TestNavigationManager::CanPruneAllButLastCommittedItem() const {
+  NOTREACHED();
+  return false;
+}
+
 void TestNavigationManager::OverrideDesktopUserAgentForNextPendingItem() {
   NOTREACHED();
 }