Add prefs for collapsed currently open tabs group in new tab page

chrome/common/pref_names.h

 // 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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 499 matching lines @@
 #if defined(OS_WIN)
 extern const char kRelaunchMode[];
 #endif
 
 extern const char kDisableVideoAndChat[];
 
 extern const char kDisableExtensions[];
 extern const char kDisablePluginFinder[];
 
 extern const char kNtpAppPageNames[];
+extern const char kNtpCollapsedCurrentlyOpenTabs[];
 extern const char kNtpCollapsedForeignSessions[];
 extern const char kNtpCollapsedRecentlyClosedTabs[];
 extern const char kNtpCollapsedSnapshotDocument[];
 extern const char kNtpCollapsedSyncPromo[];
 extern const char kNtpDateResourceServer[];
 extern const char kNtpMostVisitedURLsBlacklist[];
 extern const char kNtpPromoDesktopSessionFound[];
 extern const char kNtpPromoResourceCacheUpdate[];
 extern const char kNtpShownBookmarksFolder[];
 extern const char kNtpShownPage[];
@@ skipping 279 matching lines @@
 
 #if defined(OS_ANDROID)
 extern const char kPartnerBookmarkMappings[];
 #endif
 
 extern const char kQuickCheckEnabled[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_