DevTools: Do not invoke CPU throttling on worker targets.

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

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 2106 matching lines @@
 
 /**
  * @constructor
  * @extends {WebInspector.Object}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.CPUThrottlingManager = function()
 {
     this._targets = [];
     this._throttlingRate = 1.; // No throttling
-    WebInspector.targetManager.observeTargets(this);
+    WebInspector.targetManager.observeTargets(this, WebInspector.Target.Type.Page);
 }
 
 WebInspector.CPUThrottlingManager.prototype = {
     /**
      * @param {number} value
      */
     setRate: function(value)
     {
         this._throttlingRate = value;
         this._targets.forEach(target => target.emulationAgent().setCPUThrottlingRate(value));
@@ skipping 21 matching lines @@
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
         this._targets.remove(target, true);
     },
 
     __proto__: WebInspector.Object.prototype
 }