Added classes to enable session sync functionality.

chrome/common/notification_type.h

Index: chrome/common/notification_type.h
diff --git a/chrome/common/notification_type.h b/chrome/common/notification_type.h
index 0a0c58f9a6a539fde9568a3d09d10d784d98e105..48871b4fd2aeebfe437f70a6441196241e998d57 100644
--- a/chrome/common/notification_type.h
+++ b/chrome/common/notification_type.h
@@ -1017,6 +1017,16 @@ class NotificationType {
     // operations.
     SESSION_SERVICE_SAVED,
 
+    // A foreign session has been updated.  If a new tab page is open, the
+    // foreign session handler needs to update the new tab page's foreign
+    // session data.
+    FOREIGN_SESSION_UPDATED,
+
+    // A foreign session has been deleted.  If a new tab page is open, the
+    // foreign session handler needs to update the new tab page's foreign
+    // session data.
+    FOREIGN_SESSION_DELETED,
+
     // The syncer requires a passphrase to decrypt sensitive updates. This
     // notification is sent when the first sensitive data type is setup by the
     // user as well as anytime any the passphrase is changed in another synced