Move minidump/*_test_util.* to minidump/test

minidump/test/minidump_string_writer_test_util.h

Index: minidump/test/minidump_string_writer_test_util.h
diff --git a/minidump/minidump_string_writer_test_util.h b/minidump/test/minidump_string_writer_test_util.h
similarity index 88%
rename from minidump/minidump_string_writer_test_util.h
rename to minidump/test/minidump_string_writer_test_util.h
index db0febcf7d2b5f3509167ca1159d605ce33c8581..5db8eed1aa8aaffe8169bcd2845b228834c4e4aa 100644
--- a/minidump/minidump_string_writer_test_util.h
+++ b/minidump/test/minidump_string_writer_test_util.h
@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#ifndef CRASHPAD_MINIDUMP_TEST_MINIDUMP_STRING_WRITER_TEST_UTIL_H_
+#define CRASHPAD_MINIDUMP_TEST_MINIDUMP_STRING_WRITER_TEST_UTIL_H_
+
 #include <dbghelp.h>
 
 #include <string>
@@ -40,3 +43,5 @@ std::string MinidumpUTF8StringAtRVA(const StringFileWriter& file_writer,
 
 }  // namespace test
 }  // namespace crashpad
+
+#endif  // CRASHPAD_MINIDUMP_TEST_MINIDUMP_STRING_WRITER_TEST_UTIL_H_