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/session_info_unittest.cc b/modules/video_coding/session_info_unittest.cc
index 54173ef..282834b 100644
--- a/modules/video_coding/session_info_unittest.cc
+++ b/modules/video_coding/session_info_unittest.cc
@@ -23,7 +23,7 @@
     memset(packet_buffer_, 0, sizeof(packet_buffer_));
     memset(frame_buffer_, 0, sizeof(frame_buffer_));
     session_.Reset();
-    packet_.frameType = kVideoFrameDelta;
+    packet_.frameType = VideoFrameType::kVideoFrameDelta;
     packet_.sizeBytes = packet_buffer_size();
     packet_.dataPtr = packet_buffer_;
     packet_.seqNum = 0;
@@ -116,12 +116,12 @@
   packet_.video_header.is_first_packet_in_frame = true;
   packet_.seqNum = 0xFFFE;
   packet_.sizeBytes = packet_buffer_size();
-  packet_.frameType = kVideoFrameKey;
+  packet_.frameType = VideoFrameType::kVideoFrameKey;
   FillPacket(0);
   EXPECT_EQ(packet_buffer_size(), static_cast<size_t>(session_.InsertPacket(
                                       packet_, frame_buffer_, frame_data)));
   EXPECT_FALSE(session_.HaveLastPacket());
-  EXPECT_EQ(kVideoFrameKey, session_.FrameType());
+  EXPECT_EQ(VideoFrameType::kVideoFrameKey, session_.FrameType());
 
   packet_.video_header.is_first_packet_in_frame = false;
   packet_.markerBit = true;
@@ -138,7 +138,7 @@
   packet_.markerBit = true;
   packet_.seqNum = 2;
   packet_.sizeBytes = 0;
-  packet_.frameType = kEmptyFrame;
+  packet_.frameType = VideoFrameType::kEmptyFrame;
   EXPECT_EQ(0, session_.InsertPacket(packet_, frame_buffer_, frame_data));
   EXPECT_EQ(packet_.seqNum, session_.HighSequenceNumber());
 }
@@ -309,7 +309,7 @@
 TEST_F(TestNalUnits, OnlyReceivedEmptyPacket) {
   packet_.video_header.is_first_packet_in_frame = false;
   packet_.completeNALU = kNaluComplete;
-  packet_.frameType = kEmptyFrame;
+  packet_.frameType = VideoFrameType::kEmptyFrame;
   packet_.sizeBytes = 0;
   packet_.seqNum = 0;
   packet_.markerBit = false;