Revert "Adding a restriction for legal RID values."

This reverts commit 07f3279a730980583403b78c3762c5d246d1d9be.

Reason for revert: Suspect of producing consistent failure in some Chrome trybots, blocking rolls.

Failed test:
external/wpt/webrtc/RTCPeerConnection-addTransceiver.https.html


First failure:
https://ci.chromium.org/p/chromium/builders/try/linux-rel/64597

Original change's description:
> Adding a restriction for legal RID values.
> 
> According to the spec, RID values should be constrained to only
> alpha-numeric values. This was not enforced in our implementation to
> allow for more flexibility.
> It has been brought to our attention that some values that we currently
> consider legal (such as the '~', '=' ';' characters) might cause confusion
> with the simulcast syntax that uses these characters to indicate other
> meanings.
> What's worse, is that some characters, when used in RIDs (such as
> \u{1f937} \u{1f4a9} and \u{1f926}) cause uncontrollable laughter for some
> users which might also be a health hazard.
> This change resolves these issues by restricting RIDs to alpha-numeric.
> 
> Bug: webrtc:10491
> Change-Id: I16e262c87525d0289764beacd098e1525a355463
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/132061
> Reviewed-by: Steve Anton <steveanton@webrtc.org>
> Commit-Queue: Amit Hilbuch <amithi@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#27499}

TBR=steveanton@webrtc.org,amithi@webrtc.org

Change-Id: I89f9d8a8d3fa82de8a7d429f11ad7cc30812ba7c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:10491
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/132244
Reviewed-by: Guido Urdaneta <guidou@webrtc.org>
Commit-Queue: Guido Urdaneta <guidou@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27525}

pc/BUILD.gn

@@ -208,7 +208,6 @@ rtc_static_library("peerconnection") {
     "../logging:rtc_event_log_impl_output",
     "../media:rtc_data",
     "../media:rtc_media_base",
-    "../modules/rtp_rtcp:rtp_rtcp_format",
     "../p2p:rtc_p2p",
     "../rtc_base",
     "../rtc_base:checks",

pc/peer_connection.cc

@@ -24,14 +24,11 @@
 #include "api/jsep_session_description.h"
 #include "api/media_stream_proxy.h"
 #include "api/media_stream_track_proxy.h"
-#include "api/rtc_error.h"
-#include "api/rtp_parameters.h"
 #include "api/uma_metrics.h"
 #include "call/call.h"
 #include "logging/rtc_event_log/ice_logger.h"
 #include "logging/rtc_event_log/output/rtc_event_log_output_file.h"
 #include "logging/rtc_event_log/rtc_event_log.h"
-#include "media/base/rid_description.h"
 #include "media/sctp/sctp_transport.h"
 #include "pc/audio_rtp_receiver.h"
 #include "pc/audio_track.h"
@@ -1550,14 +1547,6 @@ PeerConnection::AddTransceiver(
         "RIDs must be provided for either all or none of the send encodings.");
   }
 
-  if (num_rids > 0 && absl::c_any_of(init.send_encodings,
-                                     [](const RtpEncodingParameters& encoding) {
-                                       return !IsLegalRsidName(encoding.rid);
-                                     })) {
-    LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
-                         "Invalid RID value provided.");
-  }
-
   if (absl::c_any_of(init.send_encodings,
                      [](const RtpEncodingParameters& encoding) {
                        return encoding.ssrc.has_value();

pc/peer_connection_simulcast_unittest.cc

@@ -15,8 +15,6 @@
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
 #include "api/create_peerconnection_factory.h"
-#include "api/media_types.h"
-#include "api/rtc_error.h"
 #include "api/rtp_transceiver_interface.h"
 #include "api/uma_metrics.h"
 #include "api/video_codecs/builtin_video_decoder_factory.h"
@@ -256,16 +254,6 @@ TEST_F(PeerConnectionSimulcastTests, MustSupplyAllOrNoRidsInSimulcast) {
   EXPECT_EQ(RTCErrorType::INVALID_PARAMETER, error.error().type());
 }
 
-// Validates that an error is returned when illegal RIDs are supplied.
-TEST_F(PeerConnectionSimulcastTests, ChecksForIllegalRidValues) {
-  auto pc_wrapper = CreatePeerConnectionWrapper();
-  auto pc = pc_wrapper->pc();
-  auto layers = CreateLayers({"f", "h", "~q"}, true);
-  auto init = CreateTransceiverInit(layers);
-  auto error = pc->AddTransceiver(cricket::MEDIA_TYPE_VIDEO, init);
-  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER, error.error().type());
-}
-
 // Validates that a single RID is removed from the encoding layer.
 TEST_F(PeerConnectionSimulcastTests, SingleRidIsRemovedFromSessionDescription) {
   auto pc = CreatePeerConnectionWrapper();

pc/sdp_serializer.cc

@@ -16,7 +16,6 @@
 
 #include "absl/algorithm/container.h"
 #include "api/jsep.h"
-#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/string_encode.h"
 #include "rtc_base/string_to_number.h"
@@ -329,10 +328,6 @@ RTCErrorOr<RidDescription> SdpSerializer::DeserializeRidDescription(
     return ParseError("Invalid RID Description format. Too many arguments.");
   }
 
-  if (!IsLegalRsidName(tokens[0])) {
-    return ParseError("Invalid RID value: " + tokens[0] + ".");
-  }
-
   if (tokens[1] != kSendDirection && tokens[1] != kReceiveDirection) {
     return ParseError("Invalid RID direction. Supported values: send / recv.");
   }

pc/sdp_serializer_unittest.cc

@@ -469,10 +469,6 @@ const char* kRidDescriptionMalformedStrings[] = {
     "1 send pt=",
     "1 send pt=abc",
     "1 recv ;;",
-    "~1 recv",
-    "1$2 send",
-    "1=2 send",
-    "1* send",
 };
 
 INSTANTIATE_TEST_SUITE_P(RidDescriptionDeserializationErrors,