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

base/mac/sdk_forward_declarations.mm

Index: base/mac/sdk_forward_declarations.mm
diff --git a/base/mac/sdk_forward_declarations.mm b/base/mac/sdk_forward_declarations.mm
index 8f774222aea8d7af34df928c65b3ca8bc953c818..7a5703228f1c3837323093ac9c9a98d255504f7e 100644
--- a/base/mac/sdk_forward_declarations.mm
+++ b/base/mac/sdk_forward_declarations.mm
@@ -20,8 +20,20 @@ NSString* const 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