Revert "Move mojo edk into mojo/edk"

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 "base/callback.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/task_runner.h"
-#include "mojo/edk/embedder/scoped_platform_handle.h"
-#include "mojo/edk/system/system_impl_export.h"
-#include "mojo/public/cpp/system/core.h"
-
-namespace mojo {
-namespace embedder {
-
-class PlatformSupport;
-
-// Must be called first to initialize the (global, singleton) system.
-MOJO_SYSTEM_IMPL_EXPORT void Init(scoped_ptr<PlatformSupport> platform_support);
-
-// A "channel" is a connection on top of an OS "pipe", on top of which Mojo
-// message pipes (etc.) can be multiplexed. It must "live" on some I/O thread.
-//
-// There are two "channel" creation/destruction APIs: the synchronous
-// |CreateChannelOnIOThread()|/|DestroyChannelOnIOThread()|, which must be
-// called from the I/O thread, and the asynchronous
-// |CreateChannel()|/|DestroyChannel()|, which may be called from any thread.
-//
-// Both creation functions have a |platform_handle| argument, which should be an
-// OS-dependent handle to one side of a suitable bidirectional OS "pipe" (e.g.,
-// a file descriptor to a socket on POSIX, a handle to a named pipe on Windows);
-// this "pipe" should be connected and ready for operation (e.g., to be written
-// to or read from).
-//
-// Both (synchronously) return a handle to the bootstrap message pipe on the
-// channel that was (or is to be) created, or |MOJO_HANDLE_INVALID| on error
-// (but note that this will happen only if, e.g., the handle table is full).
-// This message pipe may be used immediately, but since channel operation
-// actually begins asynchronously, other errors may still occur (e.g., if the
-// other end of the "pipe" is closed) and be reported in the usual way to the
-// returned handle.
-//
-// (E.g., a message written immediately to the returned handle will be queued
-// and the handle immediately closed, before the channel begins operation. In
-// this case, the channel should connect as usual, send the queued message, and
-// report that the handle was closed to the other side. The message sent may
-// have other handles, so there may still be message pipes "on" this channel.)
-//
-// Both also produce a |ChannelInfo*| (a pointer to an opaque object) -- the
-// first synchronously and second asynchronously.
-//
-// The destruction functions are similarly synchronous and asynchronous,
-// respectively, and take the |ChannelInfo*| produced by the creation function.
-// (Note: One may call |DestroyChannelOnIOThread()| with the result of
-// |CreateChannel()|, but not |DestroyChannel()| with the result of
-// |CreateChannelOnIOThread()|.)
-//
-// TODO(vtl): Figure out channel teardown.
-struct ChannelInfo;
-
-// Creates a channel; must only be called from the I/O thread. |platform_handle|
-// should be a handle to a connected OS "pipe". Eventually (even on failure),
-// the "out" value |*channel_info| should be passed to
-// |DestroyChannelOnIOThread()| to tear down the channel. Returns a handle to
-// the bootstrap message pipe.
-MOJO_SYSTEM_IMPL_EXPORT ScopedMessagePipeHandle
-    CreateChannelOnIOThread(ScopedPlatformHandle platform_handle,
-                            ChannelInfo** channel_info);
-
-typedef base::Callback<void(ChannelInfo*)> DidCreateChannelCallback;
-// Creates a channel asynchronously; may be called from any thread.
-// |platform_handle| should be a handle to a connected OS "pipe".
-// |io_thread_task_runner| should be the |TaskRunner| for the I/O thread.
-// |callback| should be the callback to call with the |ChannelInfo*|, which
-// should eventually be passed to |DestroyChannel()| (or
-// |DestroyChannelOnIOThread()|) to tear down the channel; the callback will be
-// called using |callback_thread_task_runner| if that is non-null, or otherwise
-// it will be called using |io_thread_task_runner|. Returns a handle to the
-// bootstrap message pipe.
-MOJO_SYSTEM_IMPL_EXPORT ScopedMessagePipeHandle
-    CreateChannel(ScopedPlatformHandle platform_handle,
-                  scoped_refptr<base::TaskRunner> io_thread_task_runner,
-                  DidCreateChannelCallback callback,
-                  scoped_refptr<base::TaskRunner> callback_thread_task_runner);
-
-// Destroys a channel that was created using either |CreateChannelOnIOThread()|
-// or |CreateChannel()|; must only be called from the I/O thread. |channel_info|
-// should be the "out" value from |CreateChannelOnIOThread()| or the value
-// provided to the callback to |CreateChannel()|.
-MOJO_SYSTEM_IMPL_EXPORT void DestroyChannelOnIOThread(
-    ChannelInfo* channel_info);
-
-// Destroys a channel (asynchronously) that was created using |CreateChannel()|
-// (note: NOT |CreateChannelOnIOThread()|); may be called from any thread.
-// |channel_info| should be the value provided to the callback to
-// |CreateChannel()|.
-MOJO_SYSTEM_IMPL_EXPORT void DestroyChannel(ChannelInfo* channel_info);
-
-// Inform the channel that it will soon be destroyed (doing so is optional).
-// This may be called from any thread, but the caller must ensure that this is
-// called before |DestroyChannel()| or |DestroyChannelOnIOThread()|.
-MOJO_SYSTEM_IMPL_EXPORT void WillDestroyChannelSoon(ChannelInfo* channel_info);
-
-// Creates a |MojoHandle| that wraps the given |PlatformHandle| (taking
-// ownership of it). This |MojoHandle| can then, e.g., be passed through message
-// pipes. Note: This takes ownership (and thus closes) |platform_handle| even on
-// failure, which is different from what you'd expect from a Mojo API, but it
-// makes for a more convenient embedder API.
-MOJO_SYSTEM_IMPL_EXPORT MojoResult
-    CreatePlatformHandleWrapper(ScopedPlatformHandle platform_handle,
-                                MojoHandle* platform_handle_wrapper_handle);
-// Retrieves the |PlatformHandle| that was wrapped into a |MojoHandle| (using
-// |CreatePlatformHandleWrapper()| above). Note that the |MojoHandle| must still
-// be closed separately.
-MOJO_SYSTEM_IMPL_EXPORT MojoResult
-    PassWrappedPlatformHandle(MojoHandle platform_handle_wrapper_handle,
-                              ScopedPlatformHandle* platform_handle);
-
-}  // namespace embedder
-}  // namespace mojo
-
-#endif  // MOJO_EDK_EMBEDDER_EMBEDDER_H_