TimeController: Rename Sleep to AdvanceTime.

This change renames TimeController's Sleep method to AdvanceTime, unifying
the same name with the same semantic as for downstream projects.

Bug: webrtc:11154
Change-Id: Id79bcf0eafcd0b47a76407ba220479d84df5a736
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161092
Commit-Queue: Markus Handell <handellm@webrtc.org>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29989}
diff --git a/call/rtp_video_sender_unittest.cc b/call/rtp_video_sender_unittest.cc
index 8ea4124..8190eea 100644
--- a/call/rtp_video_sender_unittest.cc
+++ b/call/rtp_video_sender_unittest.cc
@@ -160,7 +160,7 @@
 
   RtpVideoSender* router() { return router_.get(); }
   MockTransport& transport() { return transport_; }
-  void AdvanceTime(TimeDelta delta) { time_controller_.Sleep(delta); }
+  void AdvanceTime(TimeDelta delta) { time_controller_.AdvanceTime(delta); }
 
  private:
   NiceMock<MockTransport> transport_;