PlzNavigate: Refactor unit test helper functions

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 e3b56215d4d26daf3218f1b52f0133bda53ffdc0..be9bcfe812bbc7f226884c8903b10274bad3d016 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -784,6 +784,12 @@ void NavigatorImpl::CancelNavigation(FrameTreeNode* frame_tree_node) {
   navigation_request_map_.erase(frame_tree_node->frame_tree_node_id());
 }
 
+// PlzNavigate
+NavigationRequest* NavigatorImpl::GetNavigationRequestForNodeForTesting(
+    FrameTreeNode* frame_tree_node) {
+  return navigation_request_map_.get(frame_tree_node->frame_tree_node_id());
+}
+
 void NavigatorImpl::LogResourceRequestTime(
     base::TimeTicks timestamp, const GURL& url) {
   if (navigation_data_ && navigation_data_->url_ == url) {