Translate: Filter and record languages whose names Chrome doesn't show

tools/metrics/histograms/histograms.xml

 <!--
 Copyright 2013 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.
 -->
 
 <!--
 This file is used to generate a comprehensive list of Chrome histograms along
 with a detailed description for each histogram.
 
@@ skipping 10708 matching lines @@
 </histogram>
 
 <histogram name="Translate.RevertTranslation">
   <summary>
     The number of times the show original button was clicked in the translate
     infobar.
   </summary>
 </histogram>
 
 <histogram name="Translate.ServerReportedUnsupportedLanguage">
+  <obsolete>
+    Deprecated 5/2013 by Translate.UndisplayableLanguage
+  </obsolete>
   <summary>
     The number of times the detected language is not supported by Translate
     Element.
   </summary>
 </histogram>
 
 <histogram name="Translate.ShowBeforeTranslateInfobar">
   <obsolete>
     Deprecated 7/2010. No longer tracked.
   </obsolete>
@@ skipping 39 matching lines @@
   <summary>The time from starting translation to the completion.</summary>
 </histogram>
 
 <histogram name="Translate.Translate">
   <summary>
     The number of times the translate button was clicked in the translate
     infobar.
   </summary>
 </histogram>
 
+<histogram name="Translate.UndisplayableLanguage" enum="LanguageCode">
+  <summary>
+    Logs an undisplayable language included in the language list sent by the
+    Translate server. The Translate server sends the list each time the user
+    runs Chrome. This metrics tells us that there is a language which UI should
+    support but doesn't.
+  </summary>
+</histogram>
+
 <histogram name="Translate.UnsupportedLanguageAtInitiation" enum="LanguageCode">
   <summary>
     Logs an unsupported source language detected during initiation of the
     Translate feature.  This is reported when the language detector successfully
     detects the language of the webpage, but the language is not supported by
     the translation server because it is too minor.  This metric allows us to
     assess how important the unsupported language is for Google translate.
   </summary>
 </histogram>
 
@@ skipping 7619 matching lines @@
   <group name="Disabled" label="Neither extra webstore link is visible"/>
   <group name="FooterLink" label="Link in bottom right of footer"/>
   <group name="PlusIcon" label="Plus icon in apps page"/>
   <affected-histogram name="Extensions.AppLaunch"/>
   <affected-histogram name="NewTabPage.DefaultPageType"/>
 </fieldtrial>
 
 </fieldtrials>
 
 </histogram-configuration>