Implement the encoding RtpParameter scaleResolutionDownBy

Support varies by codec, especially in the simulcast case, but using
the EncoderSimulcastProxy codec should fix this.

Bug: webrtc:10069
Change-Id: Idb6a5f400ffda1cdb139004f540961a9cf85d224
Reviewed-on: https://webrtc-review.googlesource.com/c/119400
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26449}
diff --git a/media/base/fake_media_engine.h b/media/base/fake_media_engine.h
index 564b0da..a41d4e4 100644
--- a/media/base/fake_media_engine.h
+++ b/media/base/fake_media_engine.h
@@ -146,8 +146,8 @@
       const webrtc::RtpParameters& parameters) {
     auto parameters_iterator = rtp_send_parameters_.find(ssrc);
     if (parameters_iterator != rtp_send_parameters_.end()) {
-      auto result =
-          ValidateRtpParameters(parameters_iterator->second, parameters);
+      auto result = CheckRtpParametersInvalidModificationAndValues(
+          parameters_iterator->second, parameters);
       if (!result.ok())
         return result;