Update to Chromium //base at Chromium commit e3a753f17bac62738b0dbf0b36510f767b081e4b.

memory/shared_memory_handle_mac.cc

 // Copyright 2015 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_handle.h"
 
 #include <unistd.h>
 
 #include "base/posix/eintr_wrapper.h"
 
-#if defined(OS_MACOSX) && !defined(OS_IOS)
 namespace base {
 
 static_assert(sizeof(SharedMemoryHandle::Type) <=
                   sizeof(SharedMemoryHandle::TypeWireFormat),
               "Size of enum SharedMemoryHandle::Type exceeds size of type "
               "transmitted over wire.");
 
 SharedMemoryHandle::SharedMemoryHandle() : type_(POSIX), file_descriptor_() {}
 
 SharedMemoryHandle::SharedMemoryHandle(
@@ skipping 54 matching lines @@
 
 SharedMemoryHandle SharedMemoryHandle::Duplicate() const {
   DCHECK_EQ(type_, POSIX);
   int duped_handle = HANDLE_EINTR(dup(file_descriptor_.fd));
   if (duped_handle < 0)
     return SharedMemoryHandle();
   return SharedMemoryHandle(duped_handle, true);
 }
 
 }  // namespace base
-#endif  // defined(OS_MACOSX) && !defined(OS_IOS)