Add methods to base::SharedMemory to replace common SharedMemoryHandle operations.

base/memory/shared_memory.h

 // 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.
 
 #ifndef BASE_MEMORY_SHARED_MEMORY_H_
 #define BASE_MEMORY_SHARED_MEMORY_H_
 
 #include "build/build_config.h"
 
 #include <string>
@@ skipping 98 matching lines @@
 
   // Returns invalid handle (see comment above for exact definition).
   static SharedMemoryHandle NULLHandle();
 
   // Closes a shared memory handle.
   static void CloseHandle(const SharedMemoryHandle& handle);
 
   // Returns the maximum number of handles that can be open at once per process.
   static size_t GetHandleLimit();
 
+#if defined(OS_WIN) || defined(OS_POSIX)
+  // The copy shares the same underlying OS primitives. The new
+  // SharedMemoryHandle will not clean up the OS primitives when destroyed. The
+  // original must outlive the copy.
+  static SharedMemoryHandle ShallowCopyOfHandle(
+      const SharedMemoryHandle& handle);
+#endif
+
+#if defined(OS_POSIX)
+  // The underlying OS primitives are duplicated.
+  // |clean_up_resources_on_destruction| indicates whether the underlying OS
+  // primitives are cleaned up on destruction.
+  static SharedMemoryHandle DeepCopyOfHandle(
+      const SharedMemoryHandle& handle,
+      bool clean_up_resources_on_destruction);
+#endif
+
   // Creates a shared memory object as described by the options struct.
   // Returns true on success and false on failure.
   bool Create(const SharedMemoryCreateOptions& options);
 
   // Creates and maps an anonymous shared memory segment of size size.
   // Returns true on success and false on failure.
   bool CreateAndMapAnonymous(size_t size);
 
   // Creates an anonymous shared memory segment of size size.
   // Returns true on success and false on failure.
@@ skipping 188 matching lines @@
   }
 
  private:
   SharedMemory* shared_memory_;
   DISALLOW_COPY_AND_ASSIGN(SharedMemoryAutoLockDeprecated);
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_SHARED_MEMORY_H_