Remove deprecated RtpSenderInterface::GetParameters() const method

Bug: webrtc:7580
Change-Id: If6e44509256508a23c5903324f29560157974986
Reviewed-on: https://webrtc-review.googlesource.com/80962
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23518}
diff --git a/api/rtpsenderinterface.h b/api/rtpsenderinterface.h
index 8c7e751..0f235bd 100644
--- a/api/rtpsenderinterface.h
+++ b/api/rtpsenderinterface.h
@@ -54,13 +54,7 @@
   // tracks.
   virtual std::vector<std::string> stream_ids() const = 0;
 
-  // TODO(orphis): Transitional implementation
-  // Remove the const implementation and make the non-const pure virtual once
-  // when external code depending on this has updated
-  virtual RtpParameters GetParameters() { return RtpParameters(); }
-  RTC_DEPRECATED virtual RtpParameters GetParameters() const {
-    return const_cast<RtpSenderInterface*>(this)->GetParameters();
-  }
+  virtual RtpParameters GetParameters() = 0;
   // Note that only a subset of the parameters can currently be changed. See
   // rtpparameters.h
   virtual RTCError SetParameters(const RtpParameters& parameters) = 0;