Replace RegisterExternalDecoder in NetEq test VerifyTimestampPropagation.

Bug: webrtc:10080
Change-Id: Ie93f130863115c2d288cfd9f3e273a9fbc982ed6
Reviewed-on: https://webrtc-review.googlesource.com/c/112904
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25927}

test/audio_decoder_proxy_factory.h

@@ -0,0 +1,86 @@
+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef TEST_AUDIO_DECODER_PROXY_FACTORY_H_
+#define TEST_AUDIO_DECODER_PROXY_FACTORY_H_
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "absl/memory/memory.h"
+#include "api/audio_codecs/audio_decoder.h"
+#include "api/audio_codecs/audio_decoder_factory.h"
+
+namespace webrtc {
+namespace test {
+
+// An decoder factory with a single underlying AudioDecoder object, intended for
+// test purposes. Each call to MakeAudioDecoder returns a proxy for the same
+// decoder, typically a mock or fake decoder.
+class AudioDecoderProxyFactory : public AudioDecoderFactory {
+ public:
+  explicit AudioDecoderProxyFactory(AudioDecoder* decoder)
+      : decoder_(decoder) {}
+
+  // Unused by tests.
+  std::vector<AudioCodecSpec> GetSupportedDecoders() override {
+    RTC_NOTREACHED();
+    return {};
+  }
+
+  bool IsSupportedDecoder(const SdpAudioFormat& format) override {
+    return true;
+  }
+
+  std::unique_ptr<AudioDecoder> MakeAudioDecoder(
+      const SdpAudioFormat& /* format */,
+      absl::optional<AudioCodecPairId> /* codec_pair_id */) override {
+    return absl::make_unique<DecoderProxy>(decoder_);
+  }
+
+ private:
+  // Wrapper class, since CreateAudioDecoder needs to surrender
+  // ownership to the object it returns.
+  class DecoderProxy final : public AudioDecoder {
+   public:
+    explicit DecoderProxy(AudioDecoder* decoder) : decoder_(decoder) {}
+
+   private:
+    std::vector<ParseResult> ParsePayload(rtc::Buffer&& payload,
+                                          uint32_t timestamp) override {
+      return decoder_->ParsePayload(std::move(payload), timestamp);
+    }
+
+    void Reset() override { decoder_->Reset(); }
+
+    int SampleRateHz() const override { return decoder_->SampleRateHz(); }
+
+    size_t Channels() const override { return decoder_->Channels(); }
+
+    int DecodeInternal(const uint8_t* encoded,
+                       size_t encoded_len,
+                       int sample_rate_hz,
+                       int16_t* decoded,
+                       SpeechType* speech_type) override {
+      RTC_NOTREACHED();
+      return -1;
+    }
+
+    AudioDecoder* const decoder_;
+  };
+
+  AudioDecoder* const decoder_;
+};
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // TEST_AUDIO_DECODER_PROXY_FACTORY_H_