PlzNavigate: Cancel ongoing history navigations in the browser when we receive a navigation request…

content/browser/frame_host/navigator_impl.cc

Index: content/browser/frame_host/navigator_impl.cc
diff --git a/content/browser/frame_host/navigator_impl.cc b/content/browser/frame_host/navigator_impl.cc
index 997805938531dd69285fc32763d94d83c67f1a6c..57e6fa8dde428664eb3bbd81353a157cac2f230b 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -998,6 +998,17 @@ void NavigatorImpl::OnBeginNavigation(
   NavigationRequest* ongoing_navigation_request =
       frame_tree_node->navigation_request();
 
+  // Client redirects during the initial history navigation of a child frame
+  // should take precedence over the history navigation (despite being renderer-
+  // initiated).  See https://crbug.com/348447 and https://crbug.com/691168.
+  if (ongoing_navigation_request &&
+      ongoing_navigation_request->request_params()
+          .is_history_navigation_in_new_child) {
+    // Preemptively clear this local pointer before deleting the request.
+    ongoing_navigation_request = nullptr;
+    frame_tree_node->ResetNavigationRequest(false);
+  }
+
   // The renderer-initiated navigation request is ignored iff a) there is an
   // ongoing request b) which is browser or user-initiated and c) the renderer
   // request is not user-initiated.
@@ -1211,7 +1222,11 @@ void NavigatorImpl::RequestNavigation(FrameTreeNode* frame_tree_node,
   // Have the current renderer execute its beforeunload event if needed. If it
   // is not needed then NavigationRequest::BeginNavigation should be directly
   // called instead.
-  if (should_dispatch_beforeunload && !IsRendererDebugURL(dest_url)) {
+  // We don't want to dispatch a beforeunload handler if
+  // is_history_navigation_in_new_child is true. This indicates a newly created
+  // child frame which does not have a beforunload handler.
+  if (should_dispatch_beforeunload && !IsRendererDebugURL(dest_url) &&
+      !is_history_navigation_in_new_child) {

[Charlie Reis, 2017/02/18 00:22:52]

Oh, sorry!  I meant 1 line up from where it was, on 1185 (now 1182).

[ananta, 2017/02/18 00:32:05]

Done.

     navigation_request->SetWaitingForRendererResponse();
     frame_tree_node->current_frame_host()->DispatchBeforeUnload(
         true, reload_type != ReloadType::NONE);