Remove kVideoCodecUnknown from WebRTC.

There is no difference between how we handle "generic" and "unkown" codecs,
so we don't need to represent both.

Bug: webrtc:8136
Change-Id: I42b0dbc8a0bae67cc21742303c963c8dd5bde1f6
Reviewed-on: https://webrtc-review.googlesource.com/92086
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24316}
diff --git a/modules/video_coding/encoded_frame.cc b/modules/video_coding/encoded_frame.cc
index 2cb7936..91ee871 100644
--- a/modules/video_coding/encoded_frame.cc
+++ b/modules/video_coding/encoded_frame.cc
@@ -17,9 +17,9 @@
       _renderTimeMs(-1),
       _payloadType(0),
       _missingFrame(false),
-      _codec(kVideoCodecUnknown),
+      _codec(kVideoCodecGeneric),
       _rotation_set(false) {
-  _codecSpecificInfo.codecType = kVideoCodecUnknown;
+  _codecSpecificInfo.codecType = kVideoCodecGeneric;
 }
 
 VCMEncodedFrame::~VCMEncodedFrame() {
@@ -44,8 +44,8 @@
   _completeFrame = false;
   _missingFrame = false;
   _length = 0;
-  _codecSpecificInfo.codecType = kVideoCodecUnknown;
-  _codec = kVideoCodecUnknown;
+  _codecSpecificInfo.codecType = kVideoCodecGeneric;
+  _codec = kVideoCodecGeneric;
   rotation_ = kVideoRotation_0;
   content_type_ = VideoContentType::UNSPECIFIED;
   timing_.flags = VideoSendTiming::kInvalid;
@@ -138,7 +138,7 @@
         break;
       }
       default: {
-        _codecSpecificInfo.codecType = kVideoCodecUnknown;
+        _codecSpecificInfo.codecType = kVideoCodecGeneric;
         break;
       }
     }