Revert of Make SharedMemoryHandle a class on Mac.

base/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(
-    const base::FileDescriptor& file_descriptor)
-    : type_(POSIX), file_descriptor_(file_descriptor) {
-}
-
-SharedMemoryHandle::SharedMemoryHandle(int fd, bool auto_close)
-    : type_(POSIX), file_descriptor_(fd, auto_close) {
-}
-
-SharedMemoryHandle::SharedMemoryHandle(const SharedMemoryHandle& handle)
-    : type_(handle.type_), file_descriptor_(handle.file_descriptor_) {
-}
-
-SharedMemoryHandle& SharedMemoryHandle::operator=(
-    const SharedMemoryHandle& handle) {
-  if (this == &handle)
-    return *this;
-
-  type_ = handle.type_;
-  file_descriptor_ = handle.file_descriptor_;
-  return *this;
-}
-
-bool SharedMemoryHandle::operator==(const SharedMemoryHandle& handle) const {
-  // Invalid handles are always equal, even if they have different types.
-  if (!IsValid() && !handle.IsValid())
-    return true;
-
-  return type_ == handle.type_ && file_descriptor_ == handle.file_descriptor_;
-}
-
-bool SharedMemoryHandle::operator!=(const SharedMemoryHandle& handle) const {
-  return !(*this == handle);
-}
-
-SharedMemoryHandle::Type SharedMemoryHandle::GetType() const {
-  return type_;
-}
-
-bool SharedMemoryHandle::IsValid() const {
-  switch (type_) {
-    case POSIX:
-      return file_descriptor_.fd >= 0;
-    case MACH:
-      return false;
-  }
-}
-
-void SharedMemoryHandle::SetFileHandle(int fd, bool auto_close) {
-  DCHECK_EQ(type_, POSIX);
-  file_descriptor_.fd = fd;
-  file_descriptor_.auto_close = auto_close;
-}
-
-const FileDescriptor SharedMemoryHandle::GetFileDescriptor() const {
-  DCHECK_EQ(type_, POSIX);
-  return file_descriptor_;
-}
-
-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)