Bug 1223726 - Update tests; r=jdescottes

MozReview-Commit-ID: 6FR7W58WRg0

--HG--
extra : rebase_source : db75d8db16aa4358d515f885cf0f54aff5ec28fe

devtools/client/styleeditor/test/browser_styleeditor_fetch-from-netmonitor.js

@@ -34,6 +34,10 @@ add_task(function* () {
   yield ui.selectStyleSheet(ui.editors[1].styleSheet);
   yield ui.editors[1].getSourceEditor();
 
+  // Wait till there is 5 requests in Netmonitor store.
+  // (i.e. the Styleeditor panel performed one request).
+  yield waitUntil(() => getSortedRequests(store.getState()).length == 5);
+
   info("Checking Netmonitor contents.");
   let shortRequests = [];
   let longRequests = [];