IWYU: add stddef.h for size_t in CBC_CommonBitMatrix

Bug: chromium:957519
Change-Id: I241b59b354913acd23018b82c9b044719763005b
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/91070
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

AUTHORS

diff --git a/AUTHORS b/AUTHORS
index c535e36..1b65598 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -27,6 +27,7 @@
 Ralf Sippl <ralf.sippl@gmail.com>
 Robert Collyer <rcollyer99@gmail.com>
 Ryan Wiley <wileyrr@gmail.com>
+Stephan Hartmann <stha09@googlemail.com>
 Tibor Dusnoki <tdusnoki@inf.u-szeged.hu>
 Wang Qing <wangqing-hf@loongson.cn>
 Zhuo Qingliang <zhuo.dev@gmail.com>

fxbarcode/common/BC_CommonBitMatrix.h

diff --git a/fxbarcode/common/BC_CommonBitMatrix.h b/fxbarcode/common/BC_CommonBitMatrix.h
index 51022b8..4e9bf1e 100644
--- a/fxbarcode/common/BC_CommonBitMatrix.h
+++ b/fxbarcode/common/BC_CommonBitMatrix.h
@@ -7,6 +7,7 @@
 #ifndef FXBARCODE_COMMON_BC_COMMONBITMATRIX_H_
 #define FXBARCODE_COMMON_BC_COMMONBITMATRIX_H_
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include <vector>