media config: expand is_encrypted to a struct.

media/base/audio_decoder_config.h

 // Copyright (c) 2012 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_AUDIO_DECODER_CONFIG_H_
 #define MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/time/time.h"
 #include "media/base/channel_layout.h"
+#include "media/base/encryption_scheme.h"
 #include "media/base/media_export.h"
 #include "media/base/sample_format.h"
 
 namespace media {
 
 enum AudioCodec {
   // These values are histogrammed over time; do not change their ordinal
   // values.  When deleting a codec replace it with a dummy value; when adding a
   // codec, do so at the bottom before kAudioCodecMax, and update the value of
   // kAudioCodecMax to equal the new codec.
@@ skipping 30 matching lines @@
   // Constructs an uninitialized object. Clients should call Initialize() with
   // appropriate values before using.
   AudioDecoderConfig();
 
   // Constructs an initialized object.
   AudioDecoderConfig(AudioCodec codec,
                      SampleFormat sample_format,
                      ChannelLayout channel_layout,
                      int samples_per_second,
                      const std::vector<uint8_t>& extra_data,
-                     bool is_encrypted);
+                     const EncryptionScheme& encryption_scheme);
 
   ~AudioDecoderConfig();
 
   // Resets the internal state of this object. |codec_delay| is in frames.
   void Initialize(AudioCodec codec,
                   SampleFormat sample_format,
                   ChannelLayout channel_layout,
                   int samples_per_second,
                   const std::vector<uint8>& extra_data,
-                  bool is_encrypted,
+                  const EncryptionScheme& encryption_scheme,
                   base::TimeDelta seek_preroll,
                   int codec_delay);
 
   // Returns true if this object has appropriate configuration values, false
   // otherwise.
   bool IsValidConfig() const;
 
   // Returns true if all fields in |config| match this config.
   // Note: The contents of |extra_data_| are compared not the raw pointers.
   bool Matches(const AudioDecoderConfig& config) const;
@@ skipping 14 matching lines @@
   base::TimeDelta seek_preroll() const { return seek_preroll_; }
   int codec_delay() const { return codec_delay_; }
 
   // Optional byte data required to initialize audio decoders such as Vorbis
   // codebooks.
   const std::vector<uint8_t>& extra_data() const { return extra_data_; }
 
   // Whether the audio stream is potentially encrypted.
   // Note that in a potentially encrypted audio stream, individual buffers
   // can be encrypted or not encrypted.
-  bool is_encrypted() const { return is_encrypted_; }
+  bool is_encrypted() const { return encryption_scheme_.is_encrypted(); }

[ddorwin, 2015/12/10 18:36:00]

As mentioned earlier, I think this might be hiding tests that we should update
to check encryption_scheme().

[ddorwin, 2015/12/10 18:36:00]

Again, unclear if this is a "simple accessor."

[dougsteed, 2015/12/14 21:19:01]

I don't know all the usages of this class, and I don't want to impose fresh
requirements on tests for components that are not adding support for CBC
(CENCv3). So my philosophy was to not add any additional constraints on such
unaffected classes and tests. If all they are interested in is a boolean
"is_encrypted", then they can more or less continue to use EncryptionScheme as
if it was a boolean.

+
+  // Encryption scheme used for encrypted buffers.
+  const EncryptionScheme& encryption_scheme() const {
+    return encryption_scheme_;
+  }
 
  private:
   AudioCodec codec_;
   SampleFormat sample_format_;
   int bytes_per_channel_;
   ChannelLayout channel_layout_;
   int samples_per_second_;
   int bytes_per_frame_;
   std::vector<uint8_t> extra_data_;
-  bool is_encrypted_;
+  EncryptionScheme encryption_scheme_;
 
   // |seek_preroll_| is the duration of the data that the decoder must decode
   // before the decoded data is valid.
   base::TimeDelta seek_preroll_;
 
   // |codec_delay_| is the number of frames the decoder should discard before
   // returning decoded data.  This value can include both decoder delay as well
   // as padding added during encoding.
   int codec_delay_;
 
   // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
   // generated copy constructor and assignment operator. Since the extra data is
   // typically small, the performance impact is minimal.
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_