Refactor and cleanup codes. No functional changes.

protos/public/remote_attestation.proto

@@ -0,0 +1,30 @@
+////////////////////////////////////////////////////////////////////////////////
+// Copyright 2017 Google LLC.
+//
+// This software is licensed under the terms defined in the Widevine Master
+// License Agreement. For a copy of this agreement, please contact
+// widevine-licensing@google.com.
+////////////////////////////////////////////////////////////////////////////////
+//
+// Description:
+//   Remote attestation is used by ChromeOS device to authenticate itself
+//   to Widevine services for both licensing and keybox provisioning.
+
+syntax = "proto2";
+
+package widevine;
+option java_package = "com.google.video.widevine.protos";
+
+import "protos/public/client_identification.proto";
+
+message RemoteAttestation {
+  // Encrypted ClientIdentification message containing the device remote
+  // attestation certificate. Required.
+  optional EncryptedClientIdentification certificate = 1;
+  // Bytes of salt which were added to the remote attestation challenge prior to
+  // signing it. Required.
+  optional bytes salt = 2;
+  // Signed remote attestation challenge + salt. Required.
+  optional bytes signature = 3;
+}
+