Revert of [subresource_filter] Remove Forwarding NavigationThrottles

content/public/test/navigation_simulator.cc

Index: content/public/test/navigation_simulator.cc
diff --git a/content/public/test/navigation_simulator.cc b/content/public/test/navigation_simulator.cc
index 5b12daabdb34c761cf77284a48e02981e97e5972..bf2995e4f2fdf17b6ab95c23b02c56dfe4fd1112 100644
--- a/content/public/test/navigation_simulator.cc
+++ b/content/public/test/navigation_simulator.cc
@@ -483,11 +483,6 @@
   return last_throttle_check_result_.value();
 }
 
-NavigationHandle* NavigationSimulator::GetNavigationHandle() const {
-  CHECK_EQ(STARTED, state_);
-  return handle_;
-}
-
 void NavigationSimulator::DidStartNavigation(
     NavigationHandle* navigation_handle) {
   // Check if this navigation is the one we're simulating.