Remove all uses of display:block and display:inline-block.

sky/framework/elements/sky-checkbox.sky

 <!--
 // 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.
 -->
 <import src="sky-element.sky" />
 <import src="sky-icon.sky" />
 
 <sky-element attributes="checked:boolean">
 <template>
   <style>
     :host {
-      display: inline-block;
+      display: inline-flex;
       -webkit-user-select: none;
       margin: 8px 16px;
     }
   </style>
   <sky-icon size="18" />
 </template>
 <script>
 import "dart:sky";
 
 const String _kOnIcon = 'toggle/check_box_black';
@@ skipping 18 matching lines @@
   }
 
   void _handleClick(_) {
     checked = !checked;
   }
 }
 
 _init(script) => register(script, SkyCheckbox);
 </script>
 </sky-element>