[GCM] Remove the requirement for manifest key

google_apis/gcm/gcm_client.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GOOGLE_APIS_GCM_GCM_CLIENT_H_
 #define GOOGLE_APIS_GCM_GCM_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 22 matching lines @@
 // Messaging server. This interface is not supposed to be thread-safe.
 class GCM_EXPORT GCMClient {
  public:
   enum Result {
     // Successful operation.
     SUCCESS,
     // Invalid parameter.
     INVALID_PARAMETER,
     // Profile not signed in.
     NOT_SIGNED_IN,
-    // Certificate was missing. Certain operation, like register, requires it.
-    CERTIFICATE_MISSING,
     // Previous asynchronous operation is still pending to finish. Certain
     // operation, like register, is only allowed one at a time.
     ASYNC_OPERATION_PENDING,
     // Network socket error.
     NETWORK_ERROR,
     // Problem at the server.
     SERVER_ERROR,
     // Exceeded the specified TTL during message sending.
     TTL_EXCEEDED,
     // Other errors.
@@ skipping 126 matching lines @@
   // |receiver_id|: registration ID of the receiver party.
   // |message|: message to be sent.
   virtual void Send(const std::string& app_id,
                     const std::string& receiver_id,
                     const OutgoingMessage& message) = 0;
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_GCM_CLIENT_H_