WORK IN PROGRESS.

chrome/browser/ui/webui/ntp/ntp_resource_cache.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/ui/webui/ntp/ntp_resource_cache.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 465 matching lines @@
     // scale indefinitely (we'd need N*(N+1)/2 different strings to represent
     // all the combinations of unacknowledged types). But for now, we just
     // have sessions and typed urls so this is OK.
     if (unacknowledged.test(syncable::SESSIONS) &&
         unacknowledged.test(syncable::TYPED_URLS)) {
       return l10n_util::GetStringUTF16(IDS_SYNC_ADDED_SESSIONS_AND_TYPED_URLS);
     } else if (unacknowledged.test(syncable::SESSIONS)) {
       return l10n_util::GetStringUTF16(IDS_SYNC_ADDED_SESSIONS);
     } else if (unacknowledged.test(syncable::TYPED_URLS)) {
       return l10n_util::GetStringUTF16(IDS_SYNC_ADDED_TYPED_URLS);
+    } else if (unacknowledged.test(syncable::EXTENSION_SETTINGS)) {

[not at google - send to devlin, 2011/08/26 09:58:47]

I'm not sure what this is about but the CHECK on the line below gets triggered
without it, or at least, it was last week.  I'll look into it again when I get
the chance.

+      LOG(ERROR) << "Got unacknowledged settings sync something.  What???";
     } else {
       // Shouldn't be possible for any other types to be unacknowledged.
       CHECK(!unacknowledged.any());
     }
   }
   return string16();
 }
 
 void NTPResourceCache::CreateNewTabIncognitoCSS() {
   ui::ThemeProvider* tp = ThemeServiceFactory::GetForProfile(profile_);
@@ skipping 115 matching lines @@
       IDR_NEW_TAB_4_THEME_CSS : IDR_NEW_TAB_THEME_CSS;
   static const base::StringPiece new_tab_theme_css(
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           ntp_css_resource_id));
 
   // Create the string from our template and the replacements.
   std::string css_string;
   css_string = ReplaceStringPlaceholders(new_tab_theme_css, subst, NULL);
   new_tab_css_ = base::RefCountedString::TakeString(&css_string);
 }