Revert "Revert 182527" ([Sync] Make SESSIONS an implicit type)

chrome/browser/ui/webui/ntp/foreign_session_handler.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/ntp/foreign_session_handler.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 198 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 
 bool ForeignSessionHandler::IsTabSyncEnabled() {
   Profile* profile = Profile::FromWebUI(web_ui());
   ProfileSyncService* service =
       ProfileSyncServiceFactory::GetInstance()->GetForProfile(profile);
-  return service && service->GetPreferredDataTypes().Has(syncer::SESSIONS);
+  return service && service->GetPreferredDataTypes().Has(syncer::PROXY_TABS);
 }
 
 string16 ForeignSessionHandler::FormatSessionTime(const base::Time& time) {
   // Return a time like "1 hour ago", "2 days ago", etc.
   base::Time now = base::Time::Now();
   // TimeElapsed does not support negative TimeDelta values, so then we use 0.
   return TimeFormat::TimeElapsed(now < time ? base::TimeDelta() : now - time);
 }
 
 void ForeignSessionHandler::HandleGetForeignSessions(const ListValue* args) {
@@ skipping 173 matching lines @@
   dictionary->SetString("userVisibleTimestamp",
       last_synced < base::TimeDelta::FromMinutes(1) ?
           l10n_util::GetStringUTF16(IDS_SYNC_TIME_JUST_NOW) :
           TimeFormat::TimeElapsed(last_synced));
   dictionary->SetInteger("sessionId", window.window_id.id());
   dictionary->Set("tabs", tab_values.release());
   return true;
 }
 
 }  // namespace browser_sync