GN: aix port along with linux_s390x, linux_ppc64 and linux_ppc64le support.

base/files/file_enumerator_posix.cc

Index: base/files/file_enumerator_posix.cc
diff --git a/base/files/file_enumerator_posix.cc b/base/files/file_enumerator_posix.cc
index fb4010aadcad566f304a899344f1cb892b666081..cfd514b0adc29c0e4a773a7f2b0c84d01e664749 100644
--- a/base/files/file_enumerator_posix.cc
+++ b/base/files/file_enumerator_posix.cc
@@ -126,8 +126,8 @@ bool FileEnumerator::ReadDirectory(std::vector<FileInfo>* entries,
     return false;
 
 #if !defined(OS_LINUX) && !defined(OS_MACOSX) && !defined(OS_BSD) && \
-    !defined(OS_SOLARIS) && !defined(OS_ANDROID)
-  #error Port warning: depending on the definition of struct dirent, \
+    !defined(OS_SOLARIS) && !defined(OS_ANDROID) && !defined(OS_AIX)
+#error Port warning: depending on the definition of struct dirent, \
          additional space for pathname may be needed
 #endif