Delete a chain of methods in ViE, VoE and ACM

webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h

Index: webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h
diff --git a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h
index f20861398b6dc01fad151aa534b4944266f996be..a512cc75b2f71329715aa9b4a68cf64520299df3 100644
--- a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h
+++ b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.h
@@ -150,10 +150,6 @@ class AudioCodingModuleImpl final : public AudioCodingModule {
   // Smallest latency NetEq will maintain.
   int LeastRequiredDelayMs() const override;
 
-  // Impose an initial delay on playout. ACM plays silence until |delay_ms|
-  // audio is accumulated in NetEq buffer, then starts decoding payloads.
-  int SetInitialPlayoutDelay(int delay_ms) override;
-
   // Get playout timestamp.
   int PlayoutTimestamp(uint32_t* timestamp) override;