MD Extensions: use extension title for not available in guest mode page

Bug: 841509
Change-Id: I841f3487c12716d4ab0c88a6a27462729308f31c
Reviewed-on: https://chromium-review.googlesource.com/1057837Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Commit-Queue: Esmael El-Moslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558446}

chrome/app/md_extensions_strings.grdp

@@ -48,9 +48,6 @@
   <message name="IDS_MD_EXTENSIONS_ACCESSIBILITY_ERROR_MULTI_LINE" desc="Accessibility message to indicate the lines that an error spans. The lines of code will be read to the user. The place holders will be numbers.">
     Error from line <ph name="ERROR_LINE_START">$1</ph> to <ph name="ERROR_LINE_END">$2</ph>
   </message>
-  <message name="IDS_MD_EXTENSIONS_GUEST_MODE_TITLE" desc="The text displayed when viewing the page under guest-mode to indicate that guests cannot use this feature.">
-    Extension management
-  </message>
   <message name="IDS_MD_EXTENSIONS_ITEM_ID" desc="The text for the label next to the extension id.">
     &lt;span&gt;ID: &lt;/span&gt;<ph name="EXTENSION_ID">$1<ex>cfhdojbkjhnklbpkdaibdccddilifddb</ex></ph>
   </message>

chrome/browser/ui/webui/page_not_available_for_guest/page_not_available_for_guest_ui.cc

@@ -27,7 +27,7 @@ content::WebUIDataSource* CreateHTMLSource(Profile* profile,
   else if (host_name == chrome::kChromeUIHistoryHost)
     page_title = l10n_util::GetStringUTF16(IDS_HISTORY_TITLE);
   else if (host_name == chrome::kChromeUIExtensionsHost)
-    page_title = l10n_util::GetStringUTF16(IDS_MD_EXTENSIONS_GUEST_MODE_TITLE);
+    page_title = l10n_util::GetStringUTF16(IDS_MD_EXTENSIONS_TOOLBAR_TITLE);
   else
     page_title = base::UTF8ToUTF16(host_name);