Revert of - Clean up unused voice engine DTMF code.

webrtc/test/mock_voe_channel_proxy.h

Index: webrtc/test/mock_voe_channel_proxy.h
diff --git a/webrtc/test/mock_voe_channel_proxy.h b/webrtc/test/mock_voe_channel_proxy.h
index c2211f85547a11d9c1555b1d50e66294968b1117..f5c87334ccef3641bd4093d8025e616258818552 100644
--- a/webrtc/test/mock_voe_channel_proxy.h
+++ b/webrtc/test/mock_voe_channel_proxy.h
@@ -43,7 +43,8 @@
   MOCK_CONST_METHOD0(GetSpeechOutputLevelFullRange, int32_t());
   MOCK_CONST_METHOD0(GetDelayEstimate, uint32_t());
   MOCK_METHOD1(SetSendTelephoneEventPayloadType, bool(int payload_type));
-  MOCK_METHOD2(SendTelephoneEventOutband, bool(int event, int duration_ms));
+  MOCK_METHOD2(SendTelephoneEventOutband, bool(uint8_t event,
+                                               uint32_t duration_ms));
 };
 }  // namespace test
 }  // namespace webrtc