DevTools: do not allow using 'this' before call into super.

third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js

 /*
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /**
  * @constructor
  * @extends {WebInspector.UISourceCodeFrame}
  * @param {!WebInspector.UISourceCode} uiSourceCode
  */
 WebInspector.JavaScriptSourceFrame = function(uiSourceCode)
 {
+    WebInspector.UISourceCodeFrame.call(this, uiSourceCode);
+
     this._scriptsPanel = WebInspector.SourcesPanel.instance();
     this._breakpointManager = WebInspector.breakpointManager;
-
-    WebInspector.UISourceCodeFrame.call(this, uiSourceCode);
     if (uiSourceCode.project().type() === WebInspector.projectTypes.Debugger)
         this.element.classList.add("source-frame-debugger-script");
 
     this._popoverHelper = new WebInspector.ObjectPopoverHelper(this._scriptsPanel.element,
         this._getPopoverAnchor.bind(this), this._resolveObjectForPopover.bind(this), this._onHidePopover.bind(this), true);
     this._popoverHelper.setTimeout(250, 250);
 
     this.textEditor.element.addEventListener("keydown", this._onKeyDown.bind(this), true);
 
     this.textEditor.addEventListener(WebInspector.SourcesTextEditor.Events.GutterClick, this._handleGutterClick.bind(this), this);
@@ skipping 1017 matching lines @@
         this.uiSourceCode().removeEventListener(WebInspector.UISourceCode.Events.WorkingCopyChanged, this._workingCopyChanged, this);
         this.uiSourceCode().removeEventListener(WebInspector.UISourceCode.Events.WorkingCopyCommitted, this._workingCopyCommitted, this);
         this.uiSourceCode().removeEventListener(WebInspector.UISourceCode.Events.TitleChanged, this._showBlackboxInfobarIfNeeded, this);
         WebInspector.moduleSetting("skipStackFramesPattern").removeChangeListener(this._showBlackboxInfobarIfNeeded, this);
         WebInspector.moduleSetting("skipContentScripts").removeChangeListener(this._showBlackboxInfobarIfNeeded, this);
         WebInspector.UISourceCodeFrame.prototype.dispose.call(this);
     },
 
     __proto__: WebInspector.UISourceCodeFrame.prototype
 };