Add keyboard auto-repeat metrics

chrome/browser/resources/options/chromeos/keyboard_overlay.html

 <div id="keyboard-overlay" class="page" hidden>
   <div class="close-button"></div>
   <h1 i18n-content="keyboardOverlay"></h1>
   <div class="content-area">
     <table class="option-control-table">
        <tr>
          <td class="option-name" id="remap-search-key-to-label"
              i18n-content="remapSearchKeyToContent">
          </td>
          <td class="option-value">
@@ skipping 85 matching lines @@
               pref="settings.language.xkb_auto_repeat_enabled_r2"
               metric="Options_KeyboardAutoRepeat" dialog-pref>
           <span i18n-content="enableAutoRepeat"></span>
         </label>
       </div>
       <div id="auto-repeat-settings-section">
         <div class="row">
           <span class="option-name" i18n-content="autoRepeatDelay"></span>
             <span i18n-content="autoRepeatDelayLong"></span>
             <input id="auto-repeat-delay-range" type="range"
-                class="touch-slider"
+                class="touch-slider" metric="Options_KeyboardAutoRepeat_Delay"
                 pref="settings.language.xkb_auto_repeat_delay_r2" dialog-pref>
             <span i18n-content="autoRepeatDelayShort"></span>
           </div>
           <div class="row">
             <span class="option-name" i18n-content="autoRepeatRate"></span>
             <span i18n-content="autoRepeatRateSlow"></span>
             <input id="auto-repeat-interval-range" type="range"
                 class="touch-slider"
                 pref="settings.language.xkb_auto_repeat_interval_r2"
-                dialog-pref>
+                metric="Options_KeyboardAutoRepeat_Interval" dialog-pref>
             <span i18n-content="autoRepeatRateFast"></span>
           </div>
       </div>
     </div>
     <button id="keyboard-shortcuts" class="settings-row link-button"
         i18n-content="showKeyboardShortcuts"></button>
     <button id="languages-and-input-settings" class="settings-row link-button"
         i18n-content="changeLanguageAndInputSettings"></button>
   </div>
   <div class="action-area">
     <div class="button-strip">
       <button id="keyboard-cancel" type="reset" i18n-content="cancel"></button>
       <button id="keyboard-confirm" class="default-button" type="submit"
           i18n-content="ok">
       </button>
     </div>
   </div>
 </div>