Revert of Allow POSIX callers to specify a new file's mode.

base/files/file_util_posix.cc

Index: base/files/file_util_posix.cc
diff --git a/base/files/file_util_posix.cc b/base/files/file_util_posix.cc
index 1494c6a5f26d86a92ba76ffe8d988f4365459745..d86d9bcc7e94f2067b35ae74855d55a4d1bee290 100644
--- a/base/files/file_util_posix.cc
+++ b/base/files/file_util_posix.cc
@@ -693,15 +693,6 @@
   if (IGNORE_EINTR(close(fd)) < 0)
     return -1;
   return bytes_written;
-}
-
-bool WriteFileWithMode(const FilePath& filename, const char* data, int size,
-                       mode_t mode) {
-  ThreadRestrictions::AssertIOAllowed();
-  ScopedFD file(HANDLE_EINTR(creat(filename.value().c_str(), mode)));
-  if (!file.is_valid())
-    return false;
-  return WriteFileDescriptor(file.get(), data, size);
 }
 
 bool WriteFileDescriptor(const int fd, const char* data, int size) {