PlzNavigate: add support in several navigation controller unit tests

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 a8a09f7a02c9aaa3afa474c11fb18a1c1d6f8aa5..1e8bf71b67461a519296d0ae3d85149ce1251409 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -898,10 +898,12 @@ bool NavigatorImpl::RequestNavigation(
   navigation_request_map_.set(frame_tree_node_id, navigation_request.Pass());
 
   if (frame_tree_node->current_frame_host()->IsRenderFrameLive()) {
+    NavigationRequest* request_to_send =
+        navigation_request_map_.get(frame_tree_node_id);
     frame_tree_node->current_frame_host()->Send(new FrameMsg_RequestNavigation(
         frame_tree_node->current_frame_host()->GetRoutingID(),
-        navigation_request_map_.get(frame_tree_node_id)->common_params(),
-        request_params));
+        request_to_send->common_params(), request_params));
+    request_to_send->SetWaitingForRendererResponse();
     return true;
   }