media: Use native CipherMode enum type in media mojo interfaces

media/base/encryption_scheme.h

 // Copyright 2015 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 MEDIA_BASE_ENCRYPTION_SCHEME_H_
 #define MEDIA_BASE_ENCRYPTION_SCHEME_H_
 
 #include <stdint.h>
+#include <functional>
 
 #include "media/base/media_export.h"
 
 namespace media {
 
 // Specification of whether and how the stream is encrypted (in whole or part).
 class MEDIA_EXPORT EncryptionScheme {
  public:
   // Algorithm and mode used for encryption. CIPHER_MODE_UNENCRYPTED indicates
   // no encryption.
@@ skipping 50 matching lines @@
 
  private:
   CipherMode mode_ = CIPHER_MODE_UNENCRYPTED;
   Pattern pattern_;
 
   // Allow copy and assignment.
 };
 
 }  // namespace media
 
+namespace std {
+
+template <>
+struct hash<media::EncryptionScheme::CipherMode> {
+  std::size_t operator()(
+      const media::EncryptionScheme::CipherMode& mode) const {
+    return static_cast<std::size_t>(mode);
+  }
+};
+}  // namespace std

[xhwang, 2016/10/15 09:13:59]

+rockot

I have to add this, otherwise, the linker complains that:

../../mojo/public/cpp/bindings/lib/hash_util.h:22: error: undefined reference to
'std::hash<media::EncryptionScheme::CipherMode>::operator()(media::EncryptionScheme::CipherMode)
const'

I guess this is because I use this native enum in a mojom stuct (see the diff in
media_types.mojom), but this is my pure guess.

Do you see anything obvious what went wrong?

[Ken Rockot(use gerrit already), 2016/10/15 15:35:29]

I think this will do it: https://codereview.chromium.org/2415293004

+
 #endif  // MEDIA_BASE_ENCRYPTION_SCHEME_H_