diff -up chromium-85.0.4183.83/ui/gfx/linux/drm_util_linux.cc.el7-old-libdrm chromium-85.0.4183.83/ui/gfx/linux/drm_util_linux.cc
--- chromium-85.0.4183.83/ui/gfx/linux/drm_util_linux.cc.el7-old-libdrm	2020-08-31 09:38:46.043993882 -0400
+++ chromium-85.0.4183.83/ui/gfx/linux/drm_util_linux.cc	2020-08-31 09:39:21.599906318 -0400
@@ -6,6 +6,11 @@
 
 #include <drm_fourcc.h>
 
+// the libdrm in EL-7 is too old to have this define
+#ifndef DRM_FORMAT_P010
+#define DRM_FORMAT_P010 DRM_FORMAT_INVALID
+#endif
+
 #include "base/notreached.h"
 
 namespace ui {