Invalidate scrollbars when window activity changes if needed

third_party/WebKit/Source/platform/mac/VersionUtilMac.h

 // Copyright 2015 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.
 
 #ifndef VersionUtilMac_h
 #define VersionUtilMac_h
 
 #include "platform/PlatformExport.h"
 
 namespace blink {
 
-// Mavericks is Mac OS X 10.7, Darwin 11.
+// Snow Leopard is Mac OS X 10.6, Darwin 10.
+PLATFORM_EXPORT bool IsOSSnowLeopard();
+
+// Lion is Mac OS X 10.7, Darwin 11.
 PLATFORM_EXPORT bool IsOSLionOrEarlier();
 
 // Mavericks is Mac OS X 10.9, Darwin 13.
 PLATFORM_EXPORT bool IsOSMavericksOrEarlier();
 PLATFORM_EXPORT bool IsOSMavericks();
 
 // Yosemite is Mac OS X 10.10, Darwin 14.
 PLATFORM_EXPORT bool IsOSYosemite();
 
 // El Capitan is Mac OS X 10.11, Darwin 15.
 PLATFORM_EXPORT bool IsOSElCapitan();
 
 } // namespace blink
 
 #endif // VersionUtilMac_h