A few simplifications to CodecDatabase and VCMGenericDecoder

webrtc/modules/video_coding/generic_decoder.h

Index: webrtc/modules/video_coding/generic_decoder.h
diff --git a/webrtc/modules/video_coding/generic_decoder.h b/webrtc/modules/video_coding/generic_decoder.h
index 8e26a8b1afa51874caa3f39d9edf2ba788fa6b88..f7196f04c5aeca6f153376063bd7fb438996973f 100644
--- a/webrtc/modules/video_coding/generic_decoder.h
+++ b/webrtc/modules/video_coding/generic_decoder.h
@@ -11,6 +11,8 @@
 #ifndef WEBRTC_MODULES_VIDEO_CODING_GENERIC_DECODER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_GENERIC_DECODER_H_
 
+#include <memory>
+
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/include/module_common_types.h"
@@ -73,8 +75,6 @@ class VCMDecodedFrameCallback : public DecodedImageCallback {
 };
 
 class VCMGenericDecoder {
-  friend class VCMCodecDataBase;
-
  public:
   explicit VCMGenericDecoder(VideoDecoder* decoder, bool isExternal = false);
   ~VCMGenericDecoder();
@@ -92,26 +92,23 @@ class VCMGenericDecoder {
   int32_t Decode(const VCMEncodedFrame& inputFrame, int64_t nowMs);
 
   /**
-  * Free the decoder memory
-  */
-  int32_t Release();
-
-  /**
   * Set decode callback. Deregistering while decoding is illegal.
   */
   int32_t RegisterDecodeCompleteCallback(VCMDecodedFrameCallback* callback);
 
   bool External() const;
   bool PrefersLateDecoding() const;
+  bool IsSameDecoder(VideoDecoder* decoder) const {
+    return decoder_.get() == decoder;
+  }
 
  private:
   VCMDecodedFrameCallback* _callback;
   VCMFrameInformation _frameInfos[kDecoderFrameMemoryLength];
   uint32_t _nextFrameInfoIdx;
-  VideoDecoder* const _decoder;
+  std::unique_ptr<VideoDecoder> decoder_;
   VideoCodecType _codecType;
-  bool _isExternal;
-  bool _keyFrameDecoded;
+  const bool _isExternal;
   VideoContentType _last_keyframe_content_type;
 };