/usr/include/gtest/internal/ is in libgtest-dev 1.7.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gtest/internal/gtest-death-test-internal.h
/usr/include/gtest/internal/gtest-filepath.h
/usr/include/gtest/internal/gtest-internal.h
/usr/include/gtest/internal/gtest-linked_ptr.h
/usr/include/gtest/internal/gtest-param-util-generated.h
/usr/include/gtest/internal/gtest-param-util-generated.h.pump
/usr/include/gtest/internal/gtest-param-util.h
/usr/include/gtest/internal/gtest-port.h
/usr/include/gtest/internal/gtest-string.h
/usr/include/gtest/internal/gtest-tuple.h
/usr/include/gtest/internal/gtest-tuple.h.pump
/usr/include/gtest/internal/gtest-type-util.h
/usr/include/gtest/internal/gtest-type-util.h.pump