Fix accessible label for network select control in OOBE.

chrome/browser/resources/chromeos/login/oobe_screen_network.html

 <div class="step hidden animated" id="connect">
   <div class="step-contents">
     <div id="welcome-message" i18n-content="networkScreenGreeting">
     </div>
     <div class="control-with-label">
       <label for="language-select" i18n-content="selectLanguage"
              class="label menu-control"></label>
       <div class="menu-area">
         <select id="language-select" class="menu-control"></select>
       </div>
     </div>
     <div class="control-with-label">
       <label for="keyboard-select" i18n-content="selectKeyboard"
              class="label menu-control"></label>
       <div class="menu-area">
         <select id="keyboard-select" class="menu-control"></select>
       </div>
     </div>
     <div class="control-with-label">
-      <!-- TODO: This label doesn't select the network list, since the latter is
-           implemented as a div of spans.  Find a way to fix this. -->
-      <label for="networks-list" i18n-content="selectNetwork"
+      <label for="networks-list-dropdown" i18n-content="selectNetwork"
              class="label menu-control"></label>
       <div class="menu-area">
         <div id="networks-list" class="menu-control"></div>
       </div>
     </div>
   </div>
   <div id="connect-controls" class="step-controls"></div>
 </div>