[DevTools] Turn starting tracing into promise.

third_party/WebKit/Source/devtools/front_end/network/NetworkPanel.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Anthony Ricaud <rik@webkit.org>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 681 matching lines @@
       this._tracingModel.addEvents(events);
   }
 
   /**
    * @override
    */
   tracingComplete() {
     if (!this._tracingModel || !this._target)
       return;
     this._tracingModel.tracingComplete();
-    SDK.targetManager.resumeReload(this._target);
+    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(this._target);

[caseq, 2017/02/27 23:13:38]

nit: move down to actual usage.

[dgozman, 2017/02/28 01:58:17]

this._target is reset in next line.

     this._target = null;
     this._callback(new SDK.FilmStripModel(this._tracingModel, this._timeCalculator.minimumBoundary() * 1000));
     delete this._callback;
+    if (resourceTreeModel)
+      resourceTreeModel.resumeReload();
   }
 
   /**
    * @override
    */
   tracingBufferUsage() {
   }
 
   /**
    * @override
@@ skipping 24 matching lines @@
   }
 
   /**
    * @param {function(?SDK.FilmStripModel)} callback
    */
   stopRecording(callback) {
     if (!this._target)
       return;
 
     this._target.tracingManager.stop();
-    SDK.targetManager.suspendReload(this._target);
+    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(this._target);
+    if (resourceTreeModel)
+      resourceTreeModel.suspendReload();
     this._callback = callback;
     this._filmStripView.setStatusText(Common.UIString('Fetching frames...'));
   }
 };
 
 /**
  * @implements {UI.ActionDelegate}
  * @unrestricted
  */
 Network.NetworkPanel.RecordActionDelegate = class {
   /**
    * @override
    * @param {!UI.Context} context
    * @param {string} actionId
    * @return {boolean}
    */
   handleAction(context, actionId) {
     var panel = UI.context.flavor(Network.NetworkPanel);
     console.assert(panel && panel instanceof Network.NetworkPanel);
     panel._toggleRecording();
     return true;
   }
 };