GTEST_USE_OWN_FLAGFILE support

include/gtest/internal/custom/gtest-port.h

@@ -32,6 +32,8 @@
 //
 //   Flag related macros:
 //     GTEST_FLAG(flag_name)
+//     GTEST_USE_OWN_FLAGFILE_FLAG_  - Define to 0 when the system provides its
+//                                     own flagfile flag parsing.
 //     GTEST_DECLARE_bool_(name)
 //     GTEST_DECLARE_int32_(name)
 //     GTEST_DECLARE_string_(name)

include/gtest/internal/gtest-port.h

@@ -2434,6 +2434,10 @@ typedef TypeWithSize<8>::Int TimeInMillis;  // Represents time in milliseconds.
 # define GTEST_FLAG(name) FLAGS_gtest_##name
 #endif  // !defined(GTEST_FLAG)
 
+#if !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
+# define GTEST_USE_OWN_FLAGFILE_FLAG_ 1
+#endif  // !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
+
 #if !defined(GTEST_DECLARE_bool_)
 # define GTEST_FLAG_SAVER_ ::testing::internal::GTestFlagSaver