[Mac] Implement a NotificationUIManager that uses Notification Center on 10.8 for text notifications

base/mac/cocoa_protocols.h

Index: base/mac/cocoa_protocols.h
diff --git a/base/mac/cocoa_protocols.h b/base/mac/cocoa_protocols.h
index 88b07b400b58474cefaa3ecd9edd3be3083808bf..c97363265e794e7a4268d441d56dfaaef722235e 100644
--- a/base/mac/cocoa_protocols.h
+++ b/base/mac/cocoa_protocols.h
@@ -19,13 +19,13 @@
 // define these protocols at all, this file will provide empty protocol
 // definitions when used with earlier SDK versions.
 
-#if !defined(MAC_OS_X_VERSION_10_6) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_6
-
 #define DEFINE_EMPTY_PROTOCOL(p) \
 @protocol p \
 @end
 
+#if !defined(MAC_OS_X_VERSION_10_6) || \
+    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_6
+
 DEFINE_EMPTY_PROTOCOL(NSAlertDelegate)
 DEFINE_EMPTY_PROTOCOL(NSApplicationDelegate)
 DEFINE_EMPTY_PROTOCOL(NSControlTextEditingDelegate)
@@ -42,8 +42,15 @@ DEFINE_EMPTY_PROTOCOL(NSTextFieldDelegate)
 DEFINE_EMPTY_PROTOCOL(NSTextViewDelegate)
 DEFINE_EMPTY_PROTOCOL(NSWindowDelegate)
 
-#undef DEFINE_EMPTY_PROTOCOL
+#endif  // MAC_OS_X_VERSION_10_6
+
+#if !defined(MAC_OS_X_VERSION_10_8) || \
+    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_8
+
+DEFINE_EMPTY_PROTOCOL(NSUserNotificationCenterDelegate)
 
-#endif
+#endif  // MAC_OS_X_VERSION_10_6
+
+#undef DEFINE_EMPTY_PROTOCOL
 
 #endif  // BASE_COCOA_PROTOCOLS_MAC_H_