Update from chromium https://crrev.com/302282

base/mac/sdk_forward_declarations.mm

 // Copyright 2014 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 "base/mac/sdk_forward_declarations.h"
 
 // Replicate specific 10.7 SDK declarations for building with prior SDKs.
 #if !defined(MAC_OS_X_VERSION_10_7) || \
     MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
 
 NSString* const NSWindowWillEnterFullScreenNotification =
     @"NSWindowWillEnterFullScreenNotification";
 
 NSString* const NSWindowWillExitFullScreenNotification =
     @"NSWindowWillExitFullScreenNotification";
 
 NSString* const NSWindowDidEnterFullScreenNotification =
     @"NSWindowDidEnterFullScreenNotification";
 
 NSString* const NSWindowDidExitFullScreenNotification =
     @"NSWindowDidExitFullScreenNotification";
 
+NSString* const NSWindowDidChangeBackingPropertiesNotification =
+    @"NSWindowDidChangeBackingPropertiesNotification";
+
 #endif  // MAC_OS_X_VERSION_10_7
 
+// Replicate specific 10.9 SDK declarations for building with prior SDKs.
+#if !defined(MAC_OS_X_VERSION_10_9) || \
+    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_9
+
+NSString* const NSWindowDidChangeOcclusionStateNotification =
+    @"NSWindowDidChangeOcclusionStateNotification";
+
+#endif  // MAC_OS_X_VERSION_10_9
+
 // Replicate specific 10.10 SDK declarations for building with prior SDKs.
 #if !defined(MAC_OS_X_VERSION_10_10) || \
     MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_10
 
 NSString* const NSUserActivityTypeBrowsingWeb =
     @"NSUserActivityTypeBrowsingWeb";
 
 NSString* const NSAppearanceNameVibrantDark = @"NSAppearanceNameVibrantDark";
 
 #endif  // MAC_OS_X_VERSION_10_10