DevTools: rely upon shouldHideOnDetach when considering re-layout of elements and sources panels.

Source/devtools/front_end/elements/ElementsPanel.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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
@@ skipping 926 matching lines @@
         if (position === "right")
             vertically = false;
         else if (position === "bottom")
             vertically = true;
         else
             vertically = WebInspector.inspectorView.element.offsetWidth < 680;
 
         if (this.sidebarPaneView && vertically === !this._splitWidget.isVertical())
             return;
 
-        var extensionSidebarPanes = WebInspector.extensionServer.sidebarPanes();
-        if (this.sidebarPaneView && extensionSidebarPanes.length)
+        if (this.sidebarPaneView && this.sidebarPaneView.shouldHideOnDetach())
             return; // We can't reparent extension iframes.
 
+        var extensionSidebarPanes = WebInspector.extensionServer.sidebarPanes();

[caseq, 2015/08/17 22:02:42]

nuke this?

         if (this.sidebarPaneView) {
             this.sidebarPaneView.detach();
             this._splitWidget.uninstallResizer(this.sidebarPaneView.headerElement());
         }
 
         this._splitWidget.setVertical(!vertically);
 
         var computedPane = new WebInspector.SidebarPane(WebInspector.UIString("Computed"));
         computedPane.element.classList.add("composite");
         computedPane.element.classList.add("fill");
@@ skipping 93 matching lines @@
     {
         var pane = /** @type {!WebInspector.ExtensionSidebarPane} */ (event.data);
         this._addExtensionSidebarPane(pane);
     },
 
     /**
      * @param {!WebInspector.ExtensionSidebarPane} pane
      */
     _addExtensionSidebarPane: function(pane)
     {
-        if (pane.panelName() === this.name) {
-            this.setHideOnDetach();
+        if (pane.panelName() === this.name)
             this._extensionSidebarPanesContainer.addPane(pane);
-        }
     },
 
     /**
      * @param {?WebInspector.Widget} widget
      */
     setWidgetBelowDOM: function(widget)
     {
         if (widget) {
             this._elementsPanelTreeOutilneSplit.setSidebarWidget(widget);
             this._elementsPanelTreeOutilneSplit.showBoth(true);
@@ skipping 174 matching lines @@
     /**
      * @override
      * @param {!WebInspector.DOMNode} node
      * @return {?string}
      */
     decorate: function(node)
     {
         return WebInspector.UIString("Element is hidden");
     }
 }