GitLab

This is part of an effort to get rid of use of DescWrapper/NaClDesc for nexe
module loading. This is anticipation of moving nexe loading away from SRPC to
Chrome IPC.

Note that this tightens up some permissions for converting file descriptors;
I'm not sure why some were originally opened with _O_RDWR.

BUG=333950
R=bbudge@chromium.org

Review URL: https://codereview.chromium.org/291973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271918 0039d316-1c4b-4281-b951-d872f2087c98