DevTools: introduce persistence/ module

third_party/WebKit/LayoutTests/http/tests/inspector/debugger-test.js

 function scheduleTestFunction()
 {
     setTimeout(testFunction, 0);
 }
 
 var initialize_DebuggerTest = function() {
 
 InspectorTest.preloadPanel("sources");
 
 InspectorTest.startDebuggerTest = function(callback, quiet)
@@ skipping 361 matching lines @@
 {
     var panel = WebInspector.panels.sources;
     panel.showUISourceCode(uiSourceCode);
     var sourceFrame = panel.visibleView;
     if (sourceFrame.loaded)
         callback(sourceFrame);
     else
         InspectorTest.addSniffer(sourceFrame, "onTextEditorContentSet", callback && callback.bind(null, sourceFrame));
 };
 
+InspectorTest.showUISourceCodePromise = function(uiSourceCode)
+{
+    var fulfill;
+    var promise = new Promise(x => fulfill = x);
+    InspectorTest.showUISourceCode(uiSourceCode, fulfill);
+    return promise;
+}
+
 InspectorTest.showScriptSource = function(scriptName, callback)
 {
     InspectorTest.waitForScriptSource(scriptName, onScriptSource);
 
     function onScriptSource(uiSourceCode)
     {
         InspectorTest.showUISourceCode(uiSourceCode, callback);
     }
 };
 
@@ skipping 195 matching lines @@
     var listItem = threadsPane._debuggerModelToListItems.get(WebInspector.DebuggerModel.fromTarget(target));
     threadsPane._onListItemClick(listItem);
 }
 
 InspectorTest.evaluateOnCurrentCallFrame = function(code)
 {
     return new Promise(succ => InspectorTest.debuggerModel.evaluateOnSelectedCallFrame(code, "console", false, true, false, false, InspectorTest.safeWrap(succ)));
 }
 
 };