[Devtools] Regression fix for double toolbar for images in network

third_party/WebKit/Source/devtools/front_end/network/RequestPreviewView.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 40 matching lines @@
             }
         } else {
             if (this._emptyWidget) {
                 this._emptyWidget.detach();
                 delete this._emptyWidget;
             }
 
             if (!this._previewView) {
                 this._createPreviewView(handlePreviewView.bind(this));
             } else {
                 this.innerView = this._previewView;

[lushnikov, 2016/08/03 17:47:08]

this is not needed

                 handlePreviewView.call(this, this.innerView);
             }
         }
 
         /**
          * @param {!WebInspector.Widget} view
          * @this {WebInspector.RequestPreviewView}
          */
         function handlePreviewView(view)
         {
             this._previewView = view;

[lushnikov, 2016/08/03 17:47:08]

it looks to me that this._previewView is equal to this.innerView (and almost
never used). Let's simplify this!

+            var isShowing = this._previewView.isShowing();

[lushnikov, 2016/08/03 17:38:32]

Why does this code run everytime you switch to the network panel? This doesn't
look right.

             this._previewView.show(this.element);
-            if (this._previewView instanceof WebInspector.View) {
+            if (!isShowing && this._previewView instanceof WebInspector.View) {
                 var toolbar = new WebInspector.Toolbar("network-item-preview-toolbar", this.element);
                 for (var item of /** @type {!WebInspector.View} */ (this._previewView).toolbarItems())
                     toolbar.appendToolbarItem(item);
             }
             this.innerView = this._previewView;
             this._previewViewHandledForTest(this._previewView);
         }
     },
 
     /**
@@ skipping 105 matching lines @@
 
             if (this.request.resourceType() === WebInspector.resourceTypes.Other)
                 return this._createEmptyWidget();
 
             return WebInspector.RequestView.nonSourceViewForRequest(this.request);
         }
     },
 
     __proto__: WebInspector.RequestContentView.prototype
 }