[MD settings] separate spacing of controlled-by icon and control-label

chrome/browser/resources/settings/internet_page/internet_subpage.html

 <link rel="import" href="chrome://resources/cr_elements/network/cr_network_list.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="settings-internet-subpage">
   <template>
     <style include="settings-shared iron-flex">
       #networkListDiv {
         /* cr-network-list is padded to the right to allow space for a ripple */
         -webkit-padding-end: calc(var(--settings-box-row-padding) -
             var(--cr-icon-ripple-padding));
         -webkit-padding-start: var(--settings-box-row-padding);
         margin-top: var(--settings-page-vertical-margin);
         min-height: var(--settings-box-min-height);
      }
 
       #addButton {
-        -webkit-margin-end: var(--settings-control-spacing);
+        -webkit-margin-end: var(--settings-control-label-spacing);
       }
 
       #onOff {
         font-weight: 500;
       }
 
       #onOff[on] {
         color: var(--settings-toggle-color);
       }
 
@@ skipping 87 matching lines @@
             </div>
           </template>
         </template>
       </div>
 
     </template>
 
   </template>
   <script src="internet_subpage.js"></script>
 </dom-module>