DevTools: make toolbar button click targets square

Source/devtools/front_end/ui/SidebarPane.js

 /*
  * Copyright (C) 2007 Apple 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 173 matching lines @@
      * @param {!WebInspector.SidebarPane} pane
      * @param {boolean} visible
      */
     _setPaneVisible: function(pane, visible)
     {
         var title = this._titleByPane.get(pane);
         if (!title)
             return;
 
         title.element.classList.toggle("hidden", !visible);
-        pane.element.classList.toggle("hidden", !visible);
+        pane.element.classList.toggle("sidebar-pane-hidden", !visible);
     },
 
     __proto__: WebInspector.Widget.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.TabbedPane}
  */
 WebInspector.SidebarTabbedPane = function()
@@ skipping 27 matching lines @@
             if (!this.hasTab(title))
                 this.appendTab(title, title, pane);
         } else {
             if (this.hasTab(title))
                 this.closeTab(title);
         }
     },
 
     __proto__: WebInspector.TabbedPane.prototype
 }