Use javascript strict mode throughout a number of net-internals files.

chrome/browser/resources/net_internals/resizable_vertical_split_view.js

 // Copyright (c) 2011 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.
 
 /**
  * This view implements a vertically split display with a draggable divider.
  *
  *                  <<-- sizer -->>
  *
  *  +----------------------++----------------+
  *  |                      ||                |
  *  |                      ||                |
  *  |                      ||                |
  *  |                      ||                |
  *  |       leftView       ||   rightView    |
  *  |                      ||                |
  *  |                      ||                |
  *  |                      ||                |
  *  |                      ||                |
  *  |                      ||                |
  *  +----------------------++----------------+
  *
  * @param {!View} leftView The widget to position on the left.
  * @param {!View} rightView The widget to position on the right.
  * @param {!DivView} sizerView The widget that will serve as draggable divider.
  */
 var ResizableVerticalSplitView = (function() {
+  'use strict';
+
   // Minimum width to size panels to, in pixels.
-  const MIN_PANEL_WIDTH = 50;
+  var MIN_PANEL_WIDTH = 50;
 
   // We inherit from View.
   var superClass = View;
 
   /**
    * @constructor
    */
   function ResizableVerticalSplitView(leftView, rightView, sizerView) {
     // Call superclass's constructor.
     superClass.call(this);
@@ skipping 98 matching lines @@
 
       this.sizerMouseMoveListener_ = null;
       this.sizerMouseUpListener_ = null;
 
       event.preventDefault();
     }
   };
 
   return ResizableVerticalSplitView;
 })();