PlzNavigate: make content unit tests work with browser side navigation

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 a9a54b84517f62f0dbebf2bd98980e3db1dfec1e..28287b93154df79fcdfa758010771b99dff627cf 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -830,6 +830,17 @@ NavigationRequest* NavigatorImpl::GetNavigationRequestForNodeForTesting(
   return navigation_request_map_.get(frame_tree_node->frame_tree_node_id());
 }
 
+bool NavigatorImpl::IsWaitingForBeforeUnloadACK(
+    FrameTreeNode* frame_tree_node) {
+  CHECK(base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableBrowserSideNavigation));
+  NavigationRequest* request =
+    navigation_request_map_.get(frame_tree_node->frame_tree_node_id());
+  if (!request)
+    return false;
+  return request->state() == NavigationRequest::WAITING_FOR_RENDERER_RESPONSE;
+}
+
 void NavigatorImpl::LogResourceRequestTime(
     base::TimeTicks timestamp, const GURL& url) {
   if (navigation_data_ && navigation_data_->url_ == url) {