Create NavigationHandle after beforeunload with PlzNavigate.

content/browser/frame_host/navigator.h

Index: content/browser/frame_host/navigator.h
diff --git a/content/browser/frame_host/navigator.h b/content/browser/frame_host/navigator.h
index 9982cea4925a44de88bd3ccf9afa32e291f13a0c..424d828c204c6536b76f0e2373b3797023061b82 100644
--- a/content/browser/frame_host/navigator.h
+++ b/content/browser/frame_host/navigator.h
@@ -148,7 +148,8 @@ class CONTENT_EXPORT Navigator : public base::RefCounted<Navigator> {
   // response, then the request is either started or canceled, depending on the
   // value of |proceed|.
   virtual void OnBeforeUnloadACK(FrameTreeNode* frame_tree_node,
-                                 bool proceed) {}
+                                 bool proceed,
+                                 const base::TimeTicks& proceed_time) {}
 
   // PlzNavigate
   // Used to start a new renderer-initiated navigation, following a
@@ -185,8 +186,12 @@ class CONTENT_EXPORT Navigator : public base::RefCounted<Navigator> {
       const base::TimeTicks& renderer_before_unload_end_time) {}
 
   // Called when a navigation has failed or the response is 204/205 to discard
-  // the pending entry in order to avoid url spoofs.
-  virtual void DiscardPendingEntryIfNeeded(NavigationHandleImpl* handle) {}
+  // the pending entry in order to avoid url spoofs. |expected_pending_entry_id|
+  // is the ID of the pending NavigationEntry at the start of the navigation.
+  // With sufficiently bad interleaving of IPCs, this may no longer be the
+  // pending NavigationEntry, in which case the pending NavigationEntry will not
+  // be discarded.
+  virtual void DiscardPendingEntryIfNeeded(int expected_pending_entry_id) {}
 
  protected:
   friend class base::RefCounted<Navigator>;