[DevTools] Make resource tree model optional

third_party/WebKit/Source/devtools/front_end/timeline/TimelineController.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @param {!WebInspector.Target} target
  * @param {!WebInspector.TimelineLifecycleDelegate} delegate
  * @param {!WebInspector.TracingModel} tracingModel
  * @implements {WebInspector.TargetManager.Observer}
@@ skipping 152 matching lines @@
      */
     _startRecordingWithCategories: function(categories, enableJSSampling, callback)
     {
         WebInspector.targetManager.suspendAllTargets();
         var profilingStartedPromise = enableJSSampling && !Runtime.experiments.isEnabled("timelineTracingJSProfile") ?
             this._startProfilingOnAllTargets() : Promise.resolve();
         var samplingFrequencyHz = WebInspector.moduleSetting("highResolutionCpuProfiling").get() ? 10000 : 1000;
         var options = "sampling-frequency=" + samplingFrequencyHz;
         var target = this._target;
         var tracingManager = target.tracingManager;
-        target.resourceTreeModel.suspendReload();
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(target);
+        if (resourceTreeModel)
+            resourceTreeModel.suspendReload();
         profilingStartedPromise.then(tracingManager.start.bind(tracingManager, this, categories, options, onTraceStarted));
         /**
          * @param {?string} error
          */
         function onTraceStarted(error)
         {
-            target.resourceTreeModel.resumeReload();
+            if (resourceTreeModel)
+                resourceTreeModel.resumeReload();
             if (callback)
                 callback(error);
         }
     },
 
     /**
      * @override
      */
     tracingStarted: function()
     {
@@ skipping 85 matching lines @@
 
     /**
      * @param {number} progress
      * @override
      */
     eventsRetrievalProgress: function(progress)
     {
         this._delegate.loadingProgress(progress);
     }
 }