Add a method BrokerDuplicateSharedMemoryHandle() to the sandbox.

Add a method BrokerDuplicateSharedMemoryHandle() to the sandbox.

This CL is a refactor and has no intended behavior change.

On Windows, a sandboxed process calls content::BrokerDuplicateHandle to
duplicate a SharedMemoryHandle. On POSIX, a sandboxed process typically calls
dup(). I am updating the mechanism for SharedMemory on Mac to use Mach
primitives, which will require yet another method for passing
SharedMemoryHandles between unprivileged processes.

This CL adds a new method content::BrokerDuplicateSharedMemoryHandle, whose
implementation will call content::BrokerDuplicateHandle on Windows, dup() on
Linux, and some appropriate IPC on Mac. For now, the Mac implementation also
uses dup(). This solution has two benefits:
  - It can be easily extended to support a Mach based Mechanism for duplicating
  SharedMemoryHandles.
  - It extracts duplicated, cross-platform code from several locations.

BUG=466437
Committed: https://crrev.com/89ca3adb35bd9a610045344e97402b355dcb9564
Cr-Commit-Position: refs/heads/master@{#332553}

[erikchen, 2015-05-29 21:33:24]

erikchen@chromium.org changed reviewers:
+ rsesek@chromium.org

[erikchen, 2015-05-29 21:33:25]

rsesek: Please review.

Note that this CL depends on https://codereview.chromium.org/1164473003/

[Robert Sesek, 2015-06-01 22:00:41]

LGTM w/ a nit

https://codereview.chromium.org/1166473003/diff/40001/content/public/common/s...
File content/public/common/sandbox_init.h (right):

https://codereview.chromium.org/1166473003/diff/40001/content/public/common/s...
content/public/common/sandbox_init.h:40: #endif  // defined(OS_WIN) ||
defined(OS_POSIX)
Doesn't match the #if.

[erikchen, 2015-06-01 22:08:35]

https://codereview.chromium.org/1166473003/diff/40001/content/public/common/s...
File content/public/common/sandbox_init.h (right):

https://codereview.chromium.org/1166473003/diff/40001/content/public/common/s...
content/public/common/sandbox_init.h:40: #endif  // defined(OS_WIN) ||
defined(OS_POSIX)
On 2015/06/01 22:00:41, Robert Sesek wrote:
> Doesn't match the #if.

Done.

[erikchen, 2015-06-01 22:08:40]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-06-01 22:08:41]

The patchset sent to the CQ was uploaded after l-g-t-m from rsesek@chromium.org
Link to the patchset: https://codereview.chromium.org/1166473003/#ps80001
(title: "Comments from rsesek.")

[erikchen, 2015-06-01 22:10:11]

erikchen@chromium.org changed reviewers:
+ avi@chromium.org

[erikchen, 2015-06-01 22:10:11]

avi: Looking for an OWNER review.

[erikchen, 2015-06-01 22:10:18]

The CQ bit was unchecked by erikchen@chromium.org

[Avi (use Gerrit), 2015-06-02 14:58:31]

lgtm

[erikchen, 2015-06-02 16:34:00]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2015-06-02 16:35:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1166473003/80001

[commit-bot: I haz the power, 2015-06-02 16:59:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-02 16:59:01]

Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[erikchen, 2015-06-02 22:45:17]

Patchset #6 (id:100001) has been deleted

[erikchen, 2015-06-03 00:11:16]

rsesek: No response expected.

I removed the declaration and definition of BrokerDuplicateSharedMemoryHandle()
from Linux. 

My original goal was to define the method on POSIX to eliminate some duplicated
code. Since I can't define it the method on Android, there's no point to
defining it on Linux either.

[erikchen, 2015-06-03 01:22:10]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-06-03 01:22:10]

The patchset sent to the CQ was uploaded after l-g-t-m from rsesek@chromium.org,
avi@chromium.org
Link to the patchset: https://codereview.chromium.org/1166473003/#ps140001
(title: "Don't declare or define BrokerDuplicateSharedMemoryHandle() on Linux.")

[commit-bot: I haz the power, 2015-06-03 01:25:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1166473003/140001

[erikchen, 2015-06-03 01:45:30]

The CQ bit was unchecked by erikchen@chromium.org

[erikchen, 2015-06-03 01:46:23]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-06-03 01:47:33]

The CQ bit was unchecked by erikchen@chromium.org

[erikchen, 2015-06-03 01:51:58]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-06-03 01:51:59]

The patchset sent to the CQ was uploaded after l-g-t-m from rsesek@chromium.org,
avi@chromium.org
Link to the patchset: https://codereview.chromium.org/1166473003/#ps160001
(title: "Pass SharedMemoryHandle by const ref.")

[commit-bot: I haz the power, 2015-06-03 01:54:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1166473003/160001

[commit-bot: I haz the power, 2015-06-03 04:30:39]

Committed patchset #8 (id:160001)

[commit-bot: I haz the power, 2015-06-03 04:32:15]

Patchset 8 (id:??) landed as
https://crrev.com/89ca3adb35bd9a610045344e97402b355dcb9564
Cr-Commit-Position: refs/heads/master@{#332553}