Add a blocking version of the sync promo dialog

chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc

 // Copyright (c) 2012 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/sync_promo/sync_promo_ui.h"
 
 #include "base/command_line.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 277 matching lines @@
   return GetValueForKeyInQuery(url, kSyncPromoQueryKeySource, &value) ?
       value : std::string();
 }
 
 // static
 bool SyncPromoUI::UserHasSeenSyncPromoAtStartup(Profile* profile) {
   return profile->GetPrefs()->GetInteger(prefs::kSyncPromoStartupCount) > 0;
 }
 
 // static
-int SyncPromoUI::GetSyncPromoVersion() {
-  int version = 0;
+SyncPromoUI::Version SyncPromoUI::GetSyncPromoVersion() {
+  int value = 0;
   if (base::StringToInt(CommandLine::ForCurrentProcess()->
-      GetSwitchValueASCII(switches::kSyncPromoVersion), &version)) {
-    return version;
+      GetSwitchValueASCII(switches::kSyncPromoVersion), &value)) {
+    if (value >= VERSION_DEFAULT && value < VERSION_COUNT)
+      return static_cast<Version>(value);
   }
+
+  Version version;
   if (sync_promo_trial::GetSyncPromoVersionForCurrentTrial(&version))
     return version;
-  // Default promo version is 0.
-  return 0;
+
+  return VERSION_DEFAULT;
 }