A few simplifications to CodecDatabase and VCMGenericDecoder

webrtc/modules/video_coding/codec_database.h

Index: webrtc/modules/video_coding/codec_database.h
diff --git a/webrtc/modules/video_coding/codec_database.h b/webrtc/modules/video_coding/codec_database.h
index 1317e2262c2d9ddec6483389b36b185bb413f071..5f8656df8d82f2179a3fe5a752f98e3b6646b0f4 100644
--- a/webrtc/modules/video_coding/codec_database.h
+++ b/webrtc/modules/video_coding/codec_database.h
@@ -107,9 +107,9 @@ class VCMCodecDataBase {
       const VCMEncodedFrame& frame,
       VCMDecodedFrameCallback* decoded_frame_callback);
 
-  // Deletes the memory of the decoder instance |decoder|. Used to delete
-  // deep copies returned by CreateDecoderCopy().
-  void ReleaseDecoder(VCMGenericDecoder* decoder) const;
+  // Returns the current decoder (i.e. the same value as was last returned from
+  // GetDecoder();
+  VCMGenericDecoder* GetCurrentDecoder();
 
   // Returns true if the currently active decoder prefer to decode frames late.
   // That means that frames must be decoded near the render times stamp.
@@ -121,8 +121,9 @@ class VCMCodecDataBase {
   typedef std::map<uint8_t, VCMDecoderMapItem*> DecoderMap;
   typedef std::map<uint8_t, VCMExtDecoderMapItem*> ExternalDecoderMap;
 
-  VCMGenericDecoder* CreateAndInitDecoder(const VCMEncodedFrame& frame,
-                                          VideoCodec* new_codec) const;
+  std::unique_ptr<VCMGenericDecoder> CreateAndInitDecoder(
+      const VCMEncodedFrame& frame,
+      VideoCodec* new_codec) const;
 
   // Determines whether a new codec has to be created or not.
   // Checks every setting apart from maxFramerate and startBitrate.
@@ -130,9 +131,6 @@ class VCMCodecDataBase {
 
   void DeleteEncoder();
 
-  // Create an internal Decoder given a codec type
-  VCMGenericDecoder* CreateDecoder(VideoCodecType type) const;
-
   const VCMDecoderMapItem* FindDecoderItem(uint8_t payload_type) const;
 
   const VCMExtDecoderMapItem* FindExternalDecoderItem(
@@ -149,7 +147,7 @@ class VCMCodecDataBase {
   bool internal_source_;
   VCMEncodedFrameCallback* const encoded_frame_callback_;
   std::unique_ptr<VCMGenericEncoder> ptr_encoder_;
-  VCMGenericDecoder* ptr_decoder_;
+  std::unique_ptr<VCMGenericDecoder> ptr_decoder_;
   DecoderMap dec_map_;
   ExternalDecoderMap dec_external_map_;
 };  // VCMCodecDataBase