Add base/check.h or base/check_op.h based on CHECK* macros.

BUG=chromium:1144735
TEST=CQ

Exempt-From-Owner-Approval: Mechanical change involving a lot of owners.
Change-Id: Ia3b037d3d560984dbe94b8137f3782b36196ad7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2741767
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Commit-Queue: Qijiang Fan <fqj@google.com>
Tested-by: Qijiang Fan <fqj@google.com>
diff --git a/debugd/src/variant_utils.h b/debugd/src/variant_utils.h
index 025b545..8d73bf4 100644
--- a/debugd/src/variant_utils.h
+++ b/debugd/src/variant_utils.h
@@ -6,6 +6,7 @@
 #define DEBUGD_SRC_VARIANT_UTILS_H_
 
 #include <string>
+#include <base/check.h>
 #include <brillo/errors/error.h>
 #include <brillo/process/process.h>
 #include <brillo/type_name_undecorate.h>