[mojo-edk] Add support for transferring mach ports.

mojo/edk/embedder/platform_shared_buffer.cc

 // Copyright 2014 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 "mojo/edk/embedder/platform_shared_buffer.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 192 matching lines @@
 #endif
 
   shared_memory_.reset(new base::SharedMemory(handle, false));
   return true;
 }
 
 void PlatformSharedBuffer::InitFromSharedMemoryHandle(
     base::SharedMemoryHandle handle) {
   DCHECK(!shared_memory_);
 
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-  // TODO(crbug.com/582468): Support Mach shared memory.
-  CHECK(handle.GetType() == base::SharedMemoryHandle::POSIX);
-#endif
-
   // TODO(crbug.com/556587): Support read-only handles.
   shared_memory_.reset(new base::SharedMemory(handle, false));
 }
 
 PlatformSharedBufferMapping::~PlatformSharedBufferMapping() {
   Unmap();
 }
 
 void* PlatformSharedBufferMapping::GetBase() const {
   return base_;
@@ skipping 17 matching lines @@
   base_ = static_cast<char*>(shared_memory_.memory()) + offset_rounding;
   return true;
 }
 
 void PlatformSharedBufferMapping::Unmap() {
   shared_memory_.Unmap();
 }
 
 }  // namespace edk
 }  // namespace mojo