Enable shared memory handle sharing in NaCl.

base/shared_memory_nacl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/shared_memory.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
@@ skipping 119 matching lines @@
   NOTIMPLEMENTED();
 }
 
 void SharedMemory::Unlock() {
   NOTIMPLEMENTED();
 }
 
 bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
                                         SharedMemoryHandle *new_handle,
                                         bool close_self) {
-  return false;
+  const int new_fd = dup(mapped_file_);
+  if (new_fd < 0)
+    return false;

[bbudge, 2013/01/09 18:18:42]

Should we log the error here, as in shared_memory_posix.cc?
    DPLOG(ERROR) << "dup() failed.";

[teravest, 2013/01/09 19:13:15]

Done.

+
+  new_handle->fd = new_fd;
+  new_handle->auto_close = true;
+
+  if (close_self)
+    Close();
+  return true;
 }
 
 }  // namespace base