PlzNavigate: Updated navigation cancel policy for renderer-initiated requests.

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 e4afbe62a6628ddf93e7e7c52ef6c120d1189dc8..9d0972617584cc7f887d94b6378fd89708b3f18d 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -707,10 +707,20 @@ void NavigatorImpl::OnBeginNavigation(
       switches::kEnableBrowserSideNavigation));
   DCHECK(frame_tree_node);
 
-  // This is a renderer-initiated navigation, so generate a new
-  // NavigationRequest and store it in the map.
-  // TODO(clamy): Renderer-initiated navigations should not always cancel the
-  // current one.
+  NavigationRequest* ongoing_navigation_request =
+      navigation_request_map_.get(frame_tree_node->frame_tree_node_id());
+  if (ongoing_navigation_request &&
+      (ongoing_navigation_request->browser_initiated() ||
+       ongoing_navigation_request->begin_params().has_user_gesture) &&
+      !begin_params.has_user_gesture) {
+    // The renderer 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.

[clamy, 2015/02/13 14:56:35]

nit: I think it would be more readable if this comment was above the if
condition since it explains it.

[carlosk, 2015/02/13 15:57:13]

Done.

+    return;
+  }
+
+  // In all other cases the current navigation, if any, is canceled and a new
+  // NavigationRequest is created and stored in the map.
   scoped_ptr<NavigationRequest> navigation_request =
       NavigationRequest::CreateRendererInitiated(
           frame_tree_node, common_params, begin_params, body);