Delete unused types VCMTemporalDecimation, VCMFrameCount and unused error codes

Bug: None
Change-Id: I53885ce78e682619301b833d1e78e93b4184c4e4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/134160
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27764}

modules/video_coding/include/video_coding_defines.h

@@ -27,11 +27,8 @@ namespace webrtc {
 #define VCM_OK 0
 #define VCM_GENERAL_ERROR -1
 #define VCM_PARAMETER_ERROR -4
-#define VCM_CODEC_ERROR -6
-#define VCM_UNINITIALIZED -7
 #define VCM_NO_CODEC_REGISTERED -8
 #define VCM_JITTER_BUFFER_ERROR -9
-#define VCM_OLD_PACKET_ERROR -10
 
 enum {
   // Timing frames settings. Timing frames are sent every
@@ -50,15 +47,6 @@ enum VCMVideoProtection {
   kProtectionNackFEC,
 };
 
-enum VCMTemporalDecimation {
-  kBitrateOverUseDecimation,
-};
-
-struct VCMFrameCount {
-  uint32_t numKeyFrames;
-  uint32_t numDeltaFrames;
-};
-
 // Callback class used for passing decoded frames which are ready to be
 // rendered.
 class VCMReceiveCallback {