Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/web/public/test/fakes/test_web_state.h

Index: ios/web/public/test/fakes/test_web_state.h
diff --git a/ios/web/public/test/fakes/test_web_state.h b/ios/web/public/test/fakes/test_web_state.h
index 63003a3990f391cf8459acd101254b7f45ed2b4c..0770a01cd12d853817e45382c7ec6d82b77e4a0d 100644
--- a/ios/web/public/test/fakes/test_web_state.h
+++ b/ios/web/public/test/fakes/test_web_state.h
@@ -38,6 +38,8 @@ class TestWebState : public WebState {
   void Stop() override {}
   const NavigationManager* GetNavigationManager() const override;
   NavigationManager* GetNavigationManager() override;
+  CRWNavigationManagerSerialization* BuildSerializedNavigationManager()
+      override;
   CRWJSInjectionReceiver* GetJSInjectionReceiver() const override;
   void ExecuteJavaScript(const base::string16& javascript) override;
   void ExecuteJavaScript(const base::string16& javascript,