Rename Maybe to Optional

talk/media/webrtc/webrtcvoiceengine.h

Index: talk/media/webrtc/webrtcvoiceengine.h
diff --git a/talk/media/webrtc/webrtcvoiceengine.h b/talk/media/webrtc/webrtcvoiceengine.h
index b9b50bb93d47fc3bf97bfabb7d53d686c5bbeae5..33524dbf53a9cdc7bcf71913204894e29ed84608 100644
--- a/talk/media/webrtc/webrtcvoiceengine.h
+++ b/talk/media/webrtc/webrtcvoiceengine.h
@@ -168,9 +168,9 @@ class WebRtcVoiceEngine final : public webrtc::TraceCallback  {
   // values, and apply them in case they are missing in the audio options. We
   // need to do this because SetExtraOptions() will revert to defaults for
   // options which are not provided.
-  rtc::Maybe<bool> extended_filter_aec_;
-  rtc::Maybe<bool> delay_agnostic_aec_;
-  rtc::Maybe<bool> experimental_ns_;
+  rtc::Optional<bool> extended_filter_aec_;
+  rtc::Optional<bool> delay_agnostic_aec_;
+  rtc::Optional<bool> experimental_ns_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(WebRtcVoiceEngine);
 };