The following warnings are emitted when compiling against libva 2.0:

[29989/40999] CXX obj/media/gpu/gpu/vaapi_video_decode_accelerator.o
../../media/gpu/vaapi_video_decode_accelerator.cc:1227:18: warning: 'num_slice_groups_minus1' is deprecated [-Wdeprecated-declarations]
  FROM_PPS_TO_PP(num_slice_groups_minus1);
                 ^
../../../../../../build/eve-kvm/usr/include/va/va.h:2168:5: note: 'num_slice_groups_minus1' has been explicitly marked deprecated here
    va_deprecated uint8_t num_slice_groups_minus1;
    ^
../../../../../../build/eve-kvm/usr/include/va/va.h:90:38: note: expanded from macro 'va_deprecated'
#define va_deprecated __attribute__((deprecated))
                                     ^
../../media/gpu/vaapi_video_decode_accelerator.cc:1228:13: warning: 'slice_group_map_type' is deprecated [-Wdeprecated-declarations]
  pic_param.slice_group_map_type = 0;
            ^
../../../../../../build/eve-kvm/usr/include/va/va.h:2169:5: note: 'slice_group_map_type' has been explicitly marked deprecated here
    va_deprecated uint8_t slice_group_map_type;
    ^
../../../../../../build/eve-kvm/usr/include/va/va.h:90:38: note: expanded from macro 'va_deprecated'
#define va_deprecated __attribute__((deprecated))
                                     ^
../../media/gpu/vaapi_video_decode_accelerator.cc:1229:13: warning: 'slice_group_change_rate_minus1' is deprecated [-Wdeprecated-declarations]
  pic_param.slice_group_change_rate_minus1 = 0;
            ^
../../../../../../build/eve-kvm/usr/include/va/va.h:2170:5: note: 'slice_group_change_rate_minus1' has been explicitly marked deprecated here
    va_deprecated uint16_t slice_group_change_rate_minus1;
    ^
../../../../../../build/eve-kvm/usr/include/va/va.h:90:38: note: expanded from macro 'va_deprecated'
#define va_deprecated __attribute__((deprecated))

Compilation completes and the resulting binaries are working fine, but we will want to fix these nonetheless.

Careful though, if these fields have been replaced by newer ones as we want to keep allowing compilation with 1.8.3 for testing reasons (compiled binaries would never run, we only need to maintain the ability to compile). New fields should be controlled using compile-time version check.