[DevTools] Access cpu profiler only when JS capability is present.

third_party/WebKit/Source/devtools/front_end/sdk/TargetManager.js

 /*
  * Copyright 2014 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.
  */
 
 SDK.TargetManager = class extends Common.Object {
   constructor() {
     super();
     /** @type {!Array.<!SDK.Target>} */
@@ skipping 239 matching lines @@
     var networkManager = target.model(SDK.NetworkManager);
     var resourceTreeModel = target.model(SDK.ResourceTreeModel);
     if (networkManager && resourceTreeModel)
       new SDK.NetworkLog(target, resourceTreeModel, networkManager);
 
     /** @type {!SDK.RuntimeModel} */
     target.runtimeModel = /** @type {!SDK.RuntimeModel} */ (target.model(SDK.RuntimeModel));
     target.model(SDK.DebuggerModel);
     target.model(SDK.DOMModel);
     target.model(SDK.CSSModel);
-
-    /** @type {!SDK.CPUProfilerModel} */
-    target.cpuProfilerModel = /** @type {!SDK.CPUProfilerModel} */ (target.model(SDK.CPUProfilerModel));
+    target.model(SDK.CPUProfilerModel);
 
     target.tracingManager = new SDK.TracingManager(target);
 
     target.model(SDK.ServiceWorkerManager);
 
     if (target.hasTargetCapability())
       this._childTargetManagers.set(target, new SDK.ChildTargetManager(this, target, resourceTreeModel));
 
     // Force creation of models which have observers.
     for (var modelClass of this._modelObservers.keys())
@@ skipping 431 matching lines @@
   /**
    * @param {!T} model
    */
   modelRemoved(model) {},
 };
 
 /**
  * @type {!SDK.TargetManager}
  */
 SDK.targetManager = new SDK.TargetManager();