Revert of Add a NavigationThrottle to the public content/ interface

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 81cbf8a31769c2ad1331d20fc09a3f9be1cbb9e4..c5c679656570f87722b183927bd5d1313e4cd934 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -41,7 +41,6 @@
 #include "content/browser/loader/detachable_resource_handler.h"
 #include "content/browser/loader/mime_type_resource_handler.h"
 #include "content/browser/loader/navigation_resource_handler.h"
-#include "content/browser/loader/navigation_resource_throttle.h"
 #include "content/browser/loader/navigation_url_loader_impl_core.h"
 #include "content/browser/loader/power_save_block_resource_throttle.h"
 #include "content/browser/loader/redirect_to_file_resource_handler.h"
@@ -1482,16 +1481,6 @@
                                             plugin_service, request));
 
   ScopedVector<ResourceThrottle> throttles;
-
-  // Add a NavigationResourceThrottle for navigations.
-  // PlzNavigate: the throttle is unnecessary as communication with the UI
-  // thread is handled by the NavigationURLloader.
-  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableBrowserSideNavigation) &&
-      IsResourceTypeFrame(resource_type)) {
-    throttles.push_back(new NavigationResourceThrottle(request));
-  }
-
   if (delegate_) {
     delegate_->RequestBeginning(request,
                                 resource_context,