Delete WebRTC-LibaomAv1Encoder-DisableFrameDropping

This was a kill-switch for frame dropping in AV1 encoder. The frame dropping was enabled in June 2023. Since we have not heard about about any issues related to the frame dropping, we can remove the field trial.

Bug: webrtc:42225542
Change-Id: I4b2f1d5ff61e4ae3a4a7fc6711bb83f7d522fc6a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/349921
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42241}
diff --git a/experiments/field_trials.py b/experiments/field_trials.py
index 73d6437..88c6a7e 100755
--- a/experiments/field_trials.py
+++ b/experiments/field_trials.py
@@ -86,9 +86,6 @@
     FieldTrial('WebRTC-JitterEstimatorConfig',
                42224404,
                date(2024, 4, 1)),
-    FieldTrial('WebRTC-LibaomAv1Encoder-DisableFrameDropping',
-               42225542,
-               date(2024, 4, 1)),
     FieldTrial('WebRTC-LibaomAv1Encoder-MaxConsecFrameDrop',
                42226184,
                date(2024, 4, 1)),
diff --git a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
index 6a97c63..1bde9b3 100644
--- a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
+++ b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
@@ -130,9 +130,6 @@
   EncodedImageCallback* encoded_image_callback_;
   int64_t timestamp_;
   const LibaomAv1EncoderInfoSettings encoder_info_override_;
-  // TODO(webrtc:15225): Kill switch for disabling frame dropping. Remove it
-  // after frame dropping is fully rolled out.
-  bool disable_frame_dropping_;
   int max_consec_frame_drop_;
 };
 
@@ -181,8 +178,6 @@
       encoded_image_callback_(nullptr),
       timestamp_(0),
       encoder_info_override_(env.field_trials()),
-      disable_frame_dropping_(env.field_trials().IsEnabled(
-          "WebRTC-LibaomAv1Encoder-DisableFrameDropping")),
       max_consec_frame_drop_(GetMaxConsecutiveFrameDrop(env.field_trials())) {}
 
 LibaomAv1Encoder::~LibaomAv1Encoder() {
@@ -249,9 +244,7 @@
   cfg_.g_timebase.num = 1;
   cfg_.g_timebase.den = kRtpTicksPerSecond;
   cfg_.rc_target_bitrate = encoder_settings_.startBitrate;  // kilobits/sec.
-  cfg_.rc_dropframe_thresh =
-      (!disable_frame_dropping_ && encoder_settings_.GetFrameDropEnabled()) ? 30
-                                                                            : 0;
+  cfg_.rc_dropframe_thresh = encoder_settings_.GetFrameDropEnabled() ? 30 : 0;
   cfg_.g_input_bit_depth = kBitDepth;
   cfg_.kf_mode = AOM_KF_DISABLED;
   cfg_.rc_min_quantizer = kQpMin;