Moved Opus-specific payload splitting into AudioDecoderOpus.

webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc

Index: webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc
diff --git a/webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc b/webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc
index e600d2d56c1ab5947e8c5ce02cb782086ab83c76..f5460649663f81e2ccadb8ef8223307e254b7ca6 100644
--- a/webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc
+++ b/webrtc/modules/audio_coding/codecs/pcm16b/audio_decoder_pcm16b.cc
@@ -47,11 +47,10 @@ int AudioDecoderPcm16B::DecodeInternal(const uint8_t* encoded,
 
 std::vector<AudioDecoder::ParseResult> AudioDecoderPcm16B::ParsePayload(
     rtc::Buffer&& payload,
-    uint32_t timestamp,
-    bool is_primary) {
+    uint32_t timestamp) {
   const int samples_per_ms = rtc::CheckedDivExact(sample_rate_hz_, 1000);
   return LegacyEncodedAudioFrame::SplitBySamples(
-      this, std::move(payload), timestamp, is_primary,
+      this, std::move(payload), timestamp,
       samples_per_ms * 2 * num_channels_, samples_per_ms);
 }