Componentize GCM Part 1: create GCM component and move some files over

google_apis/gcm/base/encryptor.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 2014 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 SYNC_UTIL_ENCRYPTOR_H_
-#define SYNC_UTIL_ENCRYPTOR_H_
+#ifndef GOOGLE_APIS_GCM_ENCRYPTOR_H_
+#define GOOGLE_APIS_GCM_ENCRYPTOR_H_
 
 #include <string>
+#include "google_apis/gcm/base/gcm_export.h"
 
-namespace syncer {
+namespace gcm {
 
-class Encryptor {
+class GCM_EXPORT Encryptor {
  public:
   // All methods below should be thread-safe.
   virtual bool EncryptString(const std::string& plaintext,
                              std::string* ciphertext) = 0;
 
   virtual bool DecryptString(const std::string& ciphertext,
                              std::string* plaintext) = 0;
 
- protected:
   virtual ~Encryptor() {}
 };
 
-}  // namespace syncer
+}  // namespace gcm
 
-#endif  // SYNC_UTIL_ENCRYPTOR_H_
+#endif  // GOOGLE_APIS_GCM_ENCRYPTOR_H_