Replace base::SharedMemory read-only methods with GetReadOnlyHandle.

base/memory/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/memory/shared_memory.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/mman.h>
@@ skipping 107 matching lines @@
   return handle_copy;
 }
 
 void SharedMemory::Close() {
   if (shm_.IsValid()) {
     shm_.Close();
     shm_ = SharedMemoryHandle();
   }
 }
 
+SharedMemoryHandle SharedMemory::GetReadOnlyHandle() {
+  // Untrusted code can't create descriptors or handles, which is needed to
+  // drop permissions.
+  return SharedMemoryHandle();
+}
+
 bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
-                                        SharedMemoryHandle *new_handle,
-                                        bool close_self,
-                                        ShareMode share_mode) {
-  if (share_mode == SHARE_READONLY) {
-    // Untrusted code can't create descriptors or handles, which is needed to
-    // drop permissions.
-    return false;
-  }
-
+                                        SharedMemoryHandle* new_handle,
+                                        bool close_self) {
   *new_handle = shm_.Duplicate();
-
   if (close_self) {
     Unmap();
     Close();
   }
   return new_handle->IsValid();
 }
 
 }  // namespace base