DevTools: Get rid of WebInspector.TargetObserver

Source/devtools/front_end/profiler/CPUProfileView.js

 /*
  * Copyright (C) 2008 Apple 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 342 matching lines @@
             return;
 
         var profileNode = searchResult.profileNode;
         profileNode.revealAndSelect();
     },
 
     _ensureFlameChartCreated: function()
     {
         if (this._flameChart)
             return;
-        this._dataProvider = new WebInspector.CPUFlameChartDataProvider(this.profile, this._profileHeader.target());
+        this._dataProvider = new WebInspector.CPUFlameChartDataProvider(this.profile, this._profileHeader.weakTarget());
         this._flameChart = new WebInspector.CPUProfileFlameChart(this._dataProvider);
         this._flameChart.addEventListener(WebInspector.FlameChart.Events.EntrySelected, this._onEntrySelected.bind(this));
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _onEntrySelected: function(event)
     {
         var entryIndex = event.data;
@@ skipping 531 matching lines @@
     _notifyTempFileReady: function()
     {
         if (this._onTempFileReady) {
             this._onTempFileReady();
             this._onTempFileReady = null;
         }
     },
 
     __proto__: WebInspector.ProfileHeader.prototype
 }