NTP: Allow hiding tips and bookmark sync....

chrome/browser/dom_ui/shown_sections_handler.cc

 // Copyright (c) 2009 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/dom_ui/shown_sections_handler.h"
 
 #include "base/string_util.h"
 #include "base/values.h"
 #include "chrome/browser/profile.h"
 #include "chrome/common/pref_names.h"
@@ skipping 29 matching lines @@
   bool r = list->GetString(0, &mode_string);
   DCHECK(r) << "Missing value in setShownSections from the NTP Most Visited.";
 
   dom_ui_->GetProfile()->GetPrefs()->SetInteger(
       prefs::kNTPShownSections, StringToInt(mode_string));
 }
 
 // static
 void ShownSectionsHandler::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterIntegerPref(prefs::kNTPShownSections,
-      THUMB | RECENT | TIPS);
+      THUMB | RECENT | TIPS | SYNC);
 }
 
+// static
+void ShownSectionsHandler::MigrateUserPrefs(PrefService* prefs,
+                                            int old_pref_version,
+                                            int new_pref_version) {
+  if (old_pref_version < 1) {
+    int shown_sections = prefs->GetInteger(prefs::kNTPShownSections);
+    // TIPS was used in early builds of the NNTP but since it was removed before
+    // Chrome 3.0 we want to ensure that it is shown by default.
+    shown_sections |= TIPS | SYNC;
+    prefs->SetInteger(prefs::kNTPShownSections, shown_sections);
+  }
+}