Remove chrome/ code to handle App Notifications

chrome/common/extensions/extension_constants.h

Index: chrome/common/extensions/extension_constants.h
diff --git a/chrome/common/extensions/extension_constants.h b/chrome/common/extensions/extension_constants.h
index 6330e9b6e97e6b5f3cc2d2db674c776a1812f16c..9a8d6347ab903a6311930ab8bf667ecb15e0987b 100644
--- a/chrome/common/extensions/extension_constants.h
+++ b/chrome/common/extensions/extension_constants.h
@@ -261,10 +261,6 @@ namespace extension_misc {
   // The path part of the file system url used for media file systems.
   extern const char kMediaFileSystemPathPart[];
 
-  // Error indicating that the app notifications API is not accessible by split
-  // mode extensions in incognito windows.
-  extern const char kAppNotificationsIncognitoError[];
-
   // NOTE: If you change this list, you should also change kExtensionIconSizes
   // in cc file.
   enum ExtensionIcons {