Add DecryptConfig::Clone()

- Add a clone method on DecryptConfig.
- This is required for later patches for decoders and CodecPictures to
  copy and own DecryptConfigs.

Bug: 820192
Change-Id: I5ae0826e86781d876af09509a9168e8a8e5be8a6
Reviewed-on: https://chromium-review.googlesource.com/1123767Reviewed-by: John Rummell <jrummell@chromium.org>
Commit-Queue: Rintaro Kuroiwa <rkuroiwa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574002}

media/base/decrypt_config.cc

@@ -72,6 +72,10 @@ DecryptConfig::DecryptConfig(
 
 DecryptConfig::~DecryptConfig() = default;
 
+std::unique_ptr<DecryptConfig> DecryptConfig::Clone() {
+  return base::WrapUnique(new DecryptConfig(*this));
+}
+
 bool DecryptConfig::HasPattern() const {
   return encryption_pattern_.has_value();
 }
@@ -113,4 +117,6 @@ std::ostream& DecryptConfig::Print(std::ostream& os) const {
   return os;
 }
 
+DecryptConfig::DecryptConfig(const DecryptConfig& other) = default;
+
 }  // namespace media

media/base/decrypt_config.h

@@ -72,6 +72,8 @@ class MEDIA_EXPORT DecryptConfig {
     return encryption_pattern_;
   };
 
+  std::unique_ptr<DecryptConfig> Clone();
+
   // Returns whether this config has EncryptionPattern set or not.
   bool HasPattern() const;
 
@@ -82,6 +84,8 @@ class MEDIA_EXPORT DecryptConfig {
   std::ostream& Print(std::ostream& os) const;
 
  private:
+  DecryptConfig(const DecryptConfig& other);
+
   const EncryptionMode encryption_mode_;
   const std::string key_id_;
 
@@ -95,7 +99,7 @@ class MEDIA_EXPORT DecryptConfig {
   // Only specified if |encryption_mode_| requires a pattern.
   base::Optional<EncryptionPattern> encryption_pattern_;
 
-  DISALLOW_COPY_AND_ASSIGN(DecryptConfig);
+  DISALLOW_ASSIGN(DecryptConfig);
 };
 
 }  // namespace media