Remove public GenerateKeyFrame(list-of-rids) API from RtpSender

since the spec and implementation took a different route

BUG=chromium:1354101

Change-Id: I6beda0db89b9e771ad2a7b51ba739bc46e18a331
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/318200
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#40665}

api/rtp_sender_interface.h

@@ -109,11 +109,6 @@ class RTC_EXPORT RtpSenderInterface : public rtc::RefCountInterface {
       std::unique_ptr<VideoEncoderFactory::EncoderSelectorInterface>
           encoder_selector) = 0;
 
-  // TODO(crbug.com/1354101): make pure virtual again after Chrome roll.
-  virtual RTCError GenerateKeyFrame(const std::vector<std::string>& rids) {
-    return RTCError::OK();
-  }
-
  protected:
   ~RtpSenderInterface() override = default;
 };

pc/rtp_sender.h

@@ -288,6 +288,8 @@ class RtpSenderBase : public RtpSenderInternal, public ObserverInterface {
   rtc::scoped_refptr<FrameTransformerInterface> frame_transformer_;
   std::unique_ptr<VideoEncoderFactory::EncoderSelectorInterface>
       encoder_selector_;
+
+  virtual RTCError GenerateKeyFrame(const std::vector<std::string>& rids) = 0;
 };
 
 // LocalAudioSinkAdapter receives data callback as a sink to the local

pc/rtp_sender_proxy.h

@@ -52,7 +52,6 @@ PROXY_METHOD1(void,
 PROXY_METHOD1(void,
               SetEncoderSelector,
               std::unique_ptr<VideoEncoderFactory::EncoderSelectorInterface>)
-PROXY_METHOD1(RTCError, GenerateKeyFrame, const std::vector<std::string>&)
 END_PROXY_MAP(RtpSender)
 
 }  // namespace webrtc