This is part 1 (of N) of my rearranging things to make passing FDs
actually work correctly.
R=yzshen@chromium.org
Review URL: https://codereview.chromium.org/292983007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271849 0039d316-1c4b-4281-b951-d872f2087c98
Mojo is an effort to extract a common platform out of Chrome's renderer and
plugin processes that can support multiple types of sandboxed content, such as
HTML, Pepper, or NaCl.