Add a way to cancel deferred navigations in NavigationHandle

content/browser/frame_host/navigation_request.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/navigation_request.h"
 
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigation_handle_impl.h"
@@ skipping 270 matching lines @@
 void NavigationRequest::OnRequestStarted(base::TimeTicks timestamp) {
   frame_tree_node_->navigator()->LogResourceRequestTime(timestamp,
                                                         common_params_.url);
 }
 
 void NavigationRequest::OnStartChecksComplete(
     NavigationThrottle::ThrottleCheckResult result) {
   CHECK(result != NavigationThrottle::DEFER);
 
   // Abort the request if needed. This will destroy the NavigationRequest.
-  if (result == NavigationThrottle::CANCEL_AND_IGNORE) {
+  if (result == NavigationThrottle::CANCEL_AND_IGNORE ||
+      result == NavigationThrottle::CANCEL) {
+    // TODO(clamy): distinguish between CANCEL and CANCEL_AND_IGNORE.
     frame_tree_node_->ResetNavigationRequest(false);
     return;
   }
 
   loader_ = NavigationURLLoader::Create(
       frame_tree_node_->navigator()->GetController()->GetBrowserContext(),
       info_.Pass(), navigation_handle_->service_worker_handle(), this);
 }
 
 void NavigationRequest::OnRedirectChecksComplete(
     NavigationThrottle::ThrottleCheckResult result) {
   CHECK(result != NavigationThrottle::DEFER);
 
   // Abort the request if needed. This will destroy the NavigationRequest.
-  if (result == NavigationThrottle::CANCEL_AND_IGNORE) {
+  if (result == NavigationThrottle::CANCEL_AND_IGNORE ||
+      result == NavigationThrottle::CANCEL) {
+    // TODO(clamy): distinguish between CANCEL and CANCEL_AND_IGNORE.
     frame_tree_node_->ResetNavigationRequest(false);
     return;
   }
 
   loader_->FollowRedirect();
   navigation_handle_->DidRedirectNavigation(common_params_.url);
 }
 
 }  // namespace content