DevTools: do not make main panel unconditionally focused by default.

third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js

 /*
  * Copyright (C) 2012 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 125 matching lines @@
     this.suspendInvalidations();
     if (this._mainWidget)
       this._mainWidget.detach();
     this._mainWidget = widget;
     if (widget) {
       widget.element.classList.add('insertion-point-main');
       widget.element.classList.remove('insertion-point-sidebar');
       widget.attach(this);
       if (this._showMode === UI.SplitWidget.ShowMode.OnlyMain || this._showMode === UI.SplitWidget.ShowMode.Both)
         widget.showWidget(this.element);
-      this.setDefaultFocusedChild(widget);
     }
     this.resumeInvalidations();
   }
 
   /**
    * @param {!UI.Widget} widget
    */
   setSidebarWidget(widget) {
     if (this._sidebarWidget === widget)
       return;
@@ skipping 722 matching lines @@
   OnlySidebar: 'OnlySidebar'
 };
 
 /** @enum {symbol} */
 UI.SplitWidget.Events = {
   SidebarSizeChanged: Symbol('SidebarSizeChanged'),
   ShowModeChanged: Symbol('ShowModeChanged')
 };
 
 UI.SplitWidget.MinPadding = 20;