PlzNavigate: support NavigationThrottle::WillProcessResponse

content/test/test_navigation_url_loader.h

Index: content/test/test_navigation_url_loader.h
diff --git a/content/test/test_navigation_url_loader.h b/content/test/test_navigation_url_loader.h
index 9cfe1ba0191940fb7e5551d1d9ca7ae55570b385..620fac51c540775ee5f51b58322cc3b66e1c47ad 100644
--- a/content/test/test_navigation_url_loader.h
+++ b/content/test/test_navigation_url_loader.h
@@ -33,6 +33,7 @@ class TestNavigationURLLoader
 
   // NavigationURLLoader implementation.
   void FollowRedirect() override;
+  void ProceedWithResponse() override;
 
   NavigationRequestInfo* request_info() const { return request_info_.get(); }
 
@@ -47,12 +48,15 @@ class TestNavigationURLLoader
 
   int redirect_count() { return redirect_count_; }
 
+  bool response_proceeded() { return response_proceeded_; }
+
  private:
   ~TestNavigationURLLoader() override;
 
   scoped_ptr<NavigationRequestInfo> request_info_;
   NavigationURLLoaderDelegate* delegate_;
   int redirect_count_;
+  bool response_proceeded_;
 };
 
 }  // namespace content