Bug 1234571: unregister encoded-frame callback when releasing codec databases r=pkerr

media/webrtc/trunk/webrtc/modules/video_coding/main/source/generic_encoder.cc

@@ -85,6 +85,7 @@ int32_t VCMGenericEncoder::Release()
       rtc::CritScope lock(&rates_lock_);
       bit_rate_ = 0;
       frame_rate_ = 0;
+      encoder_->RegisterEncodeCompleteCallback(nullptr);
       vcm_encoded_frame_callback_ = nullptr;
     }