Implement device token fetcher

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 42a4247a80fa5db58e7e8a1cdcc542ffb22d0ec1..5986f02cb6e5dec95ff176f08d58b23c47524ae7 100644
--- a/chrome/common/notification_type.h
+++ b/chrome/common/notification_type.h
@@ -1230,6 +1230,10 @@ class NotificationType {
     // The detail of this notification is not used.
     POLICY_CHANGED,
 
+    // This notification is sent whenever the device token becomes available
+    // that the policy subsystem uses to fetch policy from the cloud.
+    DEVICE_TOKEN_AVAILABLE,
+
     // Count (must be last) ----------------------------------------------------
     // Used to determine the number of notification types.  Not valid as
     // a type parameter when registering for or posting notifications.