Use SharedMemoryHandle instead ScopedHandle as ivar for SharedMemory

base/memory/shared_memory_handle.h

 // 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.
 
 #ifndef BASE_MEMORY_SHARED_MEMORY_HANDLE_H_
 #define BASE_MEMORY_SHARED_MEMORY_HANDLE_H_
 
 #include <stddef.h>
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include "base/process/process_handle.h"
 #elif defined(OS_MACOSX) && !defined(OS_IOS)
 #include <mach/mach.h>
 #include "base/base_export.h"
 #include "base/file_descriptor_posix.h"
 #include "base/macros.h"
 #include "base/process/process_handle.h"
 #elif defined(OS_POSIX)
 #include <sys/types.h>
 #include "base/file_descriptor_posix.h"
 #endif
 
 namespace base {
 
+class SharedMemory;
+
 // SharedMemoryHandle is a platform specific type which represents
 // the underlying OS handle to a shared memory segment.
 class BASE_EXPORT SharedMemoryHandle {
  public:
   // The default constructor returns an invalid SharedMemoryHandle.
   SharedMemoryHandle();
 
   // Standard copy constructor. The new instance shares the underlying OS
   // primitives.
   SharedMemoryHandle(const SharedMemoryHandle& handle);
@@ skipping 55 matching lines @@
   // Returns false on a failure to determine the size. On success, populates the
   // output variable |size|.
   bool GetSize(size_t* size) const;
 
   // The SharedMemoryHandle must be valid.
   // Returns whether the SharedMemoryHandle was successfully mapped into memory.
   // On success, |memory| is an output variable that contains the start of the
   // mapped memory.
   bool MapAt(off_t offset, size_t bytes, void** memory, bool read_only);
 #elif defined(OS_WIN)
-  SharedMemoryHandle(HANDLE h);
-
   HANDLE GetHandle() const;
 #else
   // This constructor is deprecated, as it fails to propagate the GUID, which
   // will be added in the near future.
   // TODO(rockot): Remove this constructor once Mojo supports GUIDs.
   // https://crbug.com/713763.
   explicit SharedMemoryHandle(const base::FileDescriptor& file_descriptor);
 
   // Creates a SharedMemoryHandle from an |fd| supplied from an external
   // service.
@@ skipping 32 matching lines @@
       mach_vm_size_t size_;
 
       // Whether passing this object as a parameter to an IPC message passes
       // ownership of |memory_object_| to the IPC stack. This is meant to mimic
       // the behavior of the |auto_close| parameter of FileDescriptor.
       // Defaults to |false|.
       bool ownership_passes_to_ipc_;
     };
   };
 #elif defined(OS_WIN)
+  friend class SharedMemory;

[Nico, 2017/05/02 20:37:52]

:-(

+  // Takes implicit ownership of |h|.
+  SharedMemoryHandle(HANDLE h);
+
   HANDLE handle_;
 
   // Whether passing this object as a parameter to an IPC message passes
   // ownership of |handle_| to the IPC stack. This is meant to mimic the
   // behavior of the |auto_close| parameter of FileDescriptor. This member only
   // affects attachment-brokered SharedMemoryHandles.
   // Defaults to |false|.
   bool ownership_passes_to_ipc_;
 #else
   FileDescriptor file_descriptor_;
 #endif
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_SHARED_MEMORY_HANDLE_H_