Make VideoFrameType an enum class, and move to separate file and target

Bug: webrtc:5876, webrtc:6883
Change-Id: I1435cfa9e8e54c4ba2978261048ff3fbb993ce0e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126225
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27239}
diff --git a/modules/video_coding/fec_controller_default.cc b/modules/video_coding/fec_controller_default.cc
index 4502f2c..38fd076 100644
--- a/modules/video_coding/fec_controller_default.cc
+++ b/modules/video_coding/fec_controller_default.cc
@@ -181,7 +181,8 @@
   const size_t encoded_length = encoded_image_length;
   CritScope lock(&crit_sect_);
   if (encoded_length > 0) {
-    const bool delta_frame = encoded_image_frametype != kVideoFrameKey;
+    const bool delta_frame =
+        encoded_image_frametype != VideoFrameType::kVideoFrameKey;
     if (max_payload_size_ > 0 && encoded_length > 0) {
       const float min_packets_per_frame =
           encoded_length / static_cast<float>(max_payload_size_);