Make the mobile welcome page the only default most visited page

chrome/app/resources/locale_settings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 <grit latest_public_release="0" current_release="1">
   <outputs>
     <output filename="grit/locale_settings.h" type="rc_header">
       <emit emit_type='prepend'></emit>
     </output>
     <output filename="locale_settings_am.pak" type="data_package" lang="am" />
     <output filename="locale_settings_ar.pak" type="data_package" lang="ar" />
     <if expr="pp_ifdef('use_third_party_translations')">
       <output filename="locale_settings_ast.pak" type="data_package" lang="ast" />
@@ skipping 332 matching lines @@
       <!-- The URL for the webstore. -->
       <message name="IDS_WEBSTORE_URL" translateable="false">
         https://chrome.google.com/webstore?hl=[GRITLANGCODE]
       </message>
 
       <!-- The URL for Google Chrome welcome page. This is used for the pre -->
       <!-- populated thumbnails. -->
       <message name="IDS_CHROME_WELCOME_URL" translateable="false">
         http://www.google.com/chrome/intl/[GRITLANGCODE]/welcome.html
       </message>
+      <if expr="pp_ifdef('android')">
+        <message name="IDS_MOBILE_WELCOME_URL" translateable="false">
+          chrome://welcome
+        </message>
+      </if>
 
       <!-- The URL for Google Chrome OS welcome page. This is used for the -->
       <!-- pre populated thumbnails. -->
       <message name="IDS_CHROMEOS_WELCOME_URL" translateable="false">
         http://gweb-gettingstartedguide.appspot.com/?hl=[GRITLANGCODE]
       </message>
 
       <!-- The URL for Adobe Flash storage settings. We cannot rely on -->
       <!-- the automatic expansion of GRITLANGCODE here because Adobe does -->
       <!-- not use the language/locale code. -->
@@ skipping 94 matching lines @@
         <message name="IDS_PASSWORD_CHANGED_DIALOG_WIDTH_CHARS" use_name_for_id="true">
           70
         </message>
         <message name="IDS_PASSWORD_CHANGED_DIALOG_HEIGHT_LINES" use_name_for_id="true">
           16
         </message>
       </if>
     </messages>
   </release>
 </grit>