Revert "Implement RtpParameters.transaction_id for PC RtpSenderInterface"

This reverts commit 5faf36ef3c582350fba5ef97a3549e440d81a283.

Reason for revert: fast/peerconnection/RTCRtpSender-setParameters.html
 failing in webrtc roll, probably this CL? https://chromium-review.googlesource.com/c/chromium/src/+/1045889.

Original change's description:
> Implement RtpParameters.transaction_id for PC RtpSenderInterface
> 
> The transaction_id field should be refreshed for every getParameters()
> call and checked at each setParameters() call.
> This also checks that getParameters() was ever called to return a proper
> error code.
> 
> Bug: webrtc:7580
> Change-Id: I6c6fe289542e486fc422cdc61577982b0529d4c1
> Reviewed-on: https://webrtc-review.googlesource.com/70820
> Commit-Queue: Florent Castelli <orphis@webrtc.org>
> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
> Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
> Reviewed-by: Steve Anton <steveanton@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#23120}

TBR=steveanton@webrtc.org,deadbeef@webrtc.org,sakal@webrtc.org,kthelgason@webrtc.org,orphis@webrtc.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: webrtc:7580
Change-Id: I86da108227f8fc8d235bb2e9559377c800595b8c
Reviewed-on: https://webrtc-review.googlesource.com/74740
Reviewed-by: Max Morin <maxmorin@webrtc.org>
Commit-Queue: Max Morin <maxmorin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23134}
diff --git a/api/rtpparameters.h b/api/rtpparameters.h
index e8ff116..12e0419 100644
--- a/api/rtpparameters.h
+++ b/api/rtpparameters.h
@@ -546,6 +546,7 @@
   // Used when calling getParameters/setParameters with a PeerConnection
   // RtpSender, to ensure that outdated parameters are not unintentionally
   // applied successfully.
+  // TODO(deadbeef): Not implemented.
   std::string transaction_id;
 
   // Value to use for MID RTP header extension.
diff --git a/api/rtpsenderinterface.h b/api/rtpsenderinterface.h
index 8c7e751..01279a5 100644
--- a/api/rtpsenderinterface.h
+++ b/api/rtpsenderinterface.h
@@ -23,7 +23,6 @@
 #include "api/proxy.h"
 #include "api/rtcerror.h"
 #include "api/rtpparameters.h"
-#include "rtc_base/deprecation.h"
 #include "rtc_base/refcount.h"
 #include "rtc_base/scoped_ref_ptr.h"
 
@@ -54,13 +53,7 @@
   // 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() const = 0;
   // Note that only a subset of the parameters can currently be changed. See
   // rtpparameters.h
   virtual RTCError SetParameters(const RtpParameters& parameters) = 0;
@@ -83,7 +76,7 @@
   PROXY_CONSTMETHOD0(cricket::MediaType, media_type)
   PROXY_CONSTMETHOD0(std::string, id)
   PROXY_CONSTMETHOD0(std::vector<std::string>, stream_ids)
-  PROXY_METHOD0(RtpParameters, GetParameters);
+  PROXY_CONSTMETHOD0(RtpParameters, GetParameters);
   PROXY_METHOD1(RTCError, SetParameters, const RtpParameters&)
   PROXY_CONSTMETHOD0(rtc::scoped_refptr<DtmfSenderInterface>, GetDtmfSender);
   END_PROXY_MAP()
diff --git a/api/test/mock_rtpsender.h b/api/test/mock_rtpsender.h
index 22f391b..dda5f45 100644
--- a/api/test/mock_rtpsender.h
+++ b/api/test/mock_rtpsender.h
@@ -27,7 +27,7 @@
   MOCK_CONST_METHOD0(media_type, cricket::MediaType());
   MOCK_CONST_METHOD0(id, std::string());
   MOCK_CONST_METHOD0(stream_ids, std::vector<std::string>());
-  MOCK_METHOD0(GetParameters, RtpParameters());
+  MOCK_CONST_METHOD0(GetParameters, RtpParameters());
   MOCK_METHOD1(SetParameters, RTCError(const RtpParameters&));
   MOCK_CONST_METHOD0(GetDtmfSender, rtc::scoped_refptr<DtmfSenderInterface>());
 };