Support read-only duplicates of Mojo shared buffers.

mojo/edk/embedder/embedder.h

 // 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.
 
 #ifndef MOJO_EDK_EMBEDDER_EMBEDDER_H_
 #define MOJO_EDK_EMBEDDER_EMBEDDER_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 76 matching lines @@
 // on success.
 MOJO_SYSTEM_IMPL_EXPORT MojoResult
 PassWrappedPlatformHandle(MojoHandle platform_handle_wrapper_handle,
                           ScopedPlatformHandle* platform_handle);
 
 // Creates a |MojoHandle| that wraps the given |SharedMemoryHandle| (taking
 // ownership of it). |num_bytes| is the size of the shared memory object, and
 // |read_only| is whether the handle is a read-only handle to shared memory.
 // This |MojoHandle| is a Mojo shared buffer and can be manipulated using the
 // shared buffer functions and transferred over a message pipe.
-// TODO(crbug.com/556587): Support read-only handles. Currently, |read_only|
-// must be false.
 MOJO_SYSTEM_IMPL_EXPORT MojoResult
 CreateSharedBufferWrapper(base::SharedMemoryHandle shared_memory_handle,
                           size_t num_bytes,
                           bool read_only,
                           MojoHandle* mojo_wrapper_handle);
 
 // Retrieves the underlying |SharedMemoryHandle| from a shared buffer
 // |MojoHandle| and closes the handle. If successful, |num_bytes| will contain
 // the size of the shared memory buffer and |read_only| will contain whether the
 // buffer handle is read-only. Both |num_bytes| and |read_only| may be null.
 // Note: The value of |shared_memory_handle| may be
 // base::SharedMemory::NULLHandle(), even if this function returns success.
 // Callers should perform appropriate checks.
-// TODO(crbug.com/556587): Support read-only handles. Currently, |read_only|
-// will always return |false|.
 MOJO_SYSTEM_IMPL_EXPORT MojoResult
 PassSharedMemoryHandle(MojoHandle mojo_handle,
                        base::SharedMemoryHandle* shared_memory_handle,
                        size_t* num_bytes,
                        bool* read_only);
 
 // Initialialization/shutdown for interprocess communication (IPC) -------------
 
 // |InitIPCSupport()| sets up the subsystem for interprocess communication,
 // making the IPC functions (in the following section) available and functional.
@@ skipping 48 matching lines @@
 
 // Generates a random ASCII token string for use with CreateParentMessagePipe()
 // and CreateChildMessagePipe() above. The generated token is suitably random so
 // as to not have to worry about collisions with other generated tokens.
 MOJO_SYSTEM_IMPL_EXPORT std::string GenerateRandomToken();
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_EMBEDDER_EMBEDDER_H_