Update/delete old TODOs

Bug: webrtc:10198
Change-Id: I0341e068d792bc0b143db86e675988f4cd07ff2e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/267822
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37454}

modules/video_coding/utility/quality_scaler.cc

@@ -31,7 +31,6 @@
 namespace webrtc {
 
 namespace {
-// TODO(nisse): Delete, delegate to encoders.
 // Threshold constant used until first downscale (to permit fast rampup).
 static const int kMeasureMs = 2000;
 static const float kSamplePeriodScaleFactor = 2.5;