DevTools: Fix network overview on hidpi

Source/devtools/front_end/network/NetworkOverview.js

 // Copyright 2015 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.
 
 /**
  * @constructor
  * @extends {WebInspector.TimelineOverviewBase}
  */
 WebInspector.NetworkOverview = function()
 {
@@ skipping 17 matching lines @@
 
     WebInspector.targetManager.addModelListener(WebInspector.ResourceTreeModel, WebInspector.ResourceTreeModel.EventTypes.Load, this._loadEventFired, this);
     WebInspector.targetManager.addModelListener(WebInspector.ResourceTreeModel, WebInspector.ResourceTreeModel.EventTypes.DOMContentLoaded, this._domContentLoadedEventFired, this);
 
     this.reset();
 }
 
 /** @type {number} */
 WebInspector.NetworkOverview._bandHeight = 3;
 
-/** @type {number} */
-WebInspector.NetworkOverview._dividersBarHeight = 20;
-
 /** @typedef {{start: number, end: number}} */
 WebInspector.NetworkOverview.Window;
 
 WebInspector.NetworkOverview.prototype = {
     /**
      * @param {?WebInspector.FilmStripModel} filmStripModel
      */
     setFilmStripModel: function(filmStripModel)
     {
         this._filmStripModel = filmStripModel;
@@ skipping 264 matching lines @@
              context.beginPath();
              context.arc(x, radius, radius, 0, 2 * Math.PI, false);
              context.fill();
              context.stroke();
         }
         context.restore();
     },
 
     __proto__: WebInspector.TimelineOverviewBase.prototype
 }