[MD settings] display message about secondary install in default browser settings

chrome/app/settings_chromium_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific Chromium strings (included from chromium_strings.grd). -->
 <grit-part>
   <!-- About Page -->
   <if expr="not chromeos">
     <message name="IDS_SETTINGS_ABOUT_PROGRAM" desc="Menu title for the About Chromium page.">
       About Chromium
     </message>
     <message name="IDS_SETTINGS_GET_HELP_USING_CHROME" desc="Text of the button which takes the user to the Chrome help page.">
       Get help with Chromium
@@ skipping 23 matching lines @@
   </message>
 
   <!-- Default Browser Page -->
   <if expr="not chromeos">
     <message name="IDS_SETTINGS_DEFAULT_BROWSER_DEFAULT" desc="The text displayed when Chrome is not the default browser">
       Chromium is your default browser. Yay!
     </message>
     <message name="IDS_SETTINGS_DEFAULT_BROWSER_MAKE_DEFAULT" desc="Default browser checkbox label">
       Make Chromium the default browser
     </message>
-    <message name="IDS_SETTINGS_DEFAULT_BROWSER_UNKNOWN" desc="The text displayed when Chrome cannot determine or set the default browser">
+    <message name="IDS_SETTINGS_DEFAULT_BROWSER_ERROR" desc="The text displayed when Chrome cannot determine or set the default browser">
       Chromium cannot determine or set the default browser.
     </message>
     <message name="IDS_SETTINGS_DEFAULT_BROWSER_SECONDARY" desc="The text displayed when Chromium is installed in side-by-side mode, which does not support setting as the default browser.">
       This is a secondary installation of Chromium, and cannot be made your default browser.
     </message>
-    <message name="IDS_SETTINGS_DEFAULT_BROWSER_ERROR" desc="The text displayed when Chromium is unable to become the default browser after the user requests that it became the default browser.  This is a general error message.">
-      Chromium was not able to become the default browser.
-    </message>
   </if>
 
   <!-- Privacy Page -->
   <message name="IDS_SETTINGS_IMPROVE_BROWSING_EXPERIENCE" desc="The text in the options panel that describes how we use web services to improve browsing experience.">
     Chromium may use <ph name="BEGIN_LINK">&lt;a target="_blank" href="$1"&gt;</ph>web services<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> to improve your browsing experience. You may optionally disable these services at any time.
   </message>
 
   <!-- Sync Page -->
   <message name="IDS_SETTINGS_SYNC_SIGNIN" desc="The label that appears on the sync button in the options dialog when sync has not been set up by the user.">
     Sign in to Chromium
@@ skipping 34 matching lines @@
     <message name="IDS_SETTINGS_SYSTEM_BACKGROUND_APPS_LABEL" desc="Label for the checkbox to allow apps to run in the background, when Chrome is closed.">
       Continue running background apps when Chromium is closed
     </message>
   </if>
 
   <!-- Reset Page -->
   <message name="IDS_SETTINGS_RESET_PROFILE_FEEDBACK" desc="Feedback label in the Reset Profile Settings dialog">
     Help make Chromium better by reporting the current settings.
   </message>
 </grit-part>