Clean out unused methods from VoiceEngine and VoEBase.

voice_engine/voe_base_impl.h

Index: voice_engine/voe_base_impl.h
diff --git a/voice_engine/voe_base_impl.h b/voice_engine/voe_base_impl.h
index 36e3502e3baa36745d109c91a0334fbe4d495da6..608292ce086c710110f7e01ca1a575b183a360e3 100644
--- a/voice_engine/voe_base_impl.h
+++ b/voice_engine/voe_base_impl.h
@@ -44,20 +44,13 @@ class VoEBaseImpl : public VoEBase,
   int CreateChannel(const ChannelConfig& config) override;
   int DeleteChannel(int channel) override;
 
-  int StartReceive(int channel) override;
   int StartPlayout(int channel) override;
   int StartSend(int channel) override;
   int StopPlayout(int channel) override;
   int StopSend(int channel) override;
 
-  int GetVersion(char version[1024]) override;
-
-  int LastError() override;
-
   AudioTransport* audio_transport() override { return this; }
 
-  int AssociateSendChannel(int channel, int accociate_send_channel) override;
-
   // AudioTransport
   int32_t RecordedDataIsAvailable(const void* audio_data,
                                   const size_t number_of_frames,