Add #include of <unistd.h> to close_nocancel.cc.

Add #include of <unistd.h> to close_nocancel.cc.

On OS X the declaration of the close function looks like this:

int close(int) __asm("_close" optional extra stuff);

If we do not include unistd.h the close_nocancel.cc translation unit does not
see the asm label. This is technically an ODR violation, but not normally a
significant one, because close will get mangled to _close by the compiler
anyway. However under LLVM LTO the mangled symbol is internally given a
different name to the unmangled symbol, and the linker gets confused by the
multiple declarations with the same mangled name.

This also lets us simplify this code by defining the close function itself
(which will receive its name from the asm label in the declaration) rather
than trying to guess what the extra stuff is and naming the function we
define after that.

BUG=471146
R=thakis@chromium.org,mark@chromium.org

Committed: https://crrev.com/f16a8246620a9494b5d38a45b8da72d51a305ec8
Cr-Commit-Position: refs/heads/master@{#322620}

[Mark Mentovai, 2015-03-27 12:12:51]

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc
File base/mac/close_nocancel.cc (right):

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc#...
base/mac/close_nocancel.cc:32: // label on the declaration of the close
function, so we receive that name
Reword avoiding “we,” “our.”

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc#...
base/mac/close_nocancel.cc:49: // chosen, or when there's a choice between
UNIX2003 and pre-UNIX2003 and
This first sentence is kind of silly now.

[pcc1, 2015-03-27 17:46:56]

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc
File base/mac/close_nocancel.cc (right):

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc#...
base/mac/close_nocancel.cc:32: // label on the declaration of the close
function, so we receive that name
On 2015/03/27 12:12:50, Mark Mentovai wrote:
> Reword avoiding “we,” “our.”

Done.

https://codereview.chromium.org/1036123003/diff/1/base/mac/close_nocancel.cc#...
base/mac/close_nocancel.cc:49: // chosen, or when there's a choice between
UNIX2003 and pre-UNIX2003 and
On 2015/03/27 12:12:51, Mark Mentovai wrote:
> This first sentence is kind of silly now.

Done.

[Mark Mentovai, 2015-03-27 17:49:58]

LGTM

[pcc1, 2015-03-27 17:51:13]

The CQ bit was checked by pcc@chromium.org

[commit-bot: I haz the power, 2015-03-27 17:51:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1036123003/20001

[commit-bot: I haz the power, 2015-03-27 19:05:32]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-27 19:06:45]

Patchset 2 (id:??) landed as
https://crrev.com/f16a8246620a9494b5d38a45b8da72d51a305ec8
Cr-Commit-Position: refs/heads/master@{#322620}