Revert of mac: Add auto-close and share-read-only functionality to SharedMemory. (patchset #5 id:80001 of https://codereview.chromium.org/1418113003/ )

Reason for revert:
New unit-tests failing on 10.8

http://build.chromium.org/p/chromium.mac/builders/Mac10.8%20Tests/builds/10139/steps/base_unittests/logs/SharedMemoryMacMultiProcessTest.MachShareToProcessReadonly

Original issue's description:
> mac: Add auto-close and share-read-only functionality to Mach based SharedMemory.
>
> base::FileDescriptor has a property |auto_close| that is used to indicate that
> when the object is passed to an IPC message, the message takes ownership of the
> underlying OS handle. Since SharedMemoryHandle needs to be interchangeable with
> base::FileDescriptor, I added a property with similar functionality named
> |ownership_passes_to_ipc_|.
>
> The method ShareToProcess() is used to lower the current and maximum protection
> of the underlying OS handle before it is transferred to a different process. I
> implemented this functionality for Mach memory objects.
>
> BUG=535711
>
> Committed: https://crrev.com/033bbbcb63cab781552dfb435c035131c423de30
> Cr-Commit-Position: refs/heads/master@{#355880}

TBR=mark@chromium.org,tsepez@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=535711

Review URL: https://codereview.chromium.org/1421933002

Cr-Commit-Position: refs/heads/master@{#355908}

1 files changed, 0 insertions, 6 deletions

diff --git a/ipc/ipc_message_utils.cc b/ipc/ipc_message_utils.cc
index 0180d74..278d7be 100644
--- a/ipc/ipc_message_utils.cc
+++ b/ipc/ipc_message_utils.cc
@@ -563,12 +563,6 @@ void ParamTraits<base::SharedMemoryHandle>::Write(Message* m,
       bool result = p.GetSize(&size);
       DCHECK(result);
       ParamTraits<size_t>::Write(m, size);
-
-      // If the caller intended to pass ownership to the IPC stack, release a
-      // reference.
-      if (p.OwnershipPassesToIPC())
-        p.Close();
-
       break;
   }
 }