Make the embedder API use the ChannelManager.

mojo/edk/embedder/embedder.h

Index: mojo/edk/embedder/embedder.h
diff --git a/mojo/edk/embedder/embedder.h b/mojo/edk/embedder/embedder.h
index 11a352ccef0bcb0520683f2eee3ae26810949871..460f70c718041d94049752020f4cfe26306fdf87 100644
--- a/mojo/edk/embedder/embedder.h
+++ b/mojo/edk/embedder/embedder.h
@@ -32,10 +32,12 @@ MOJO_SYSTEM_IMPL_EXPORT Configuration* GetConfiguration();
 // 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.
+// There are two channel creation APIs: |CreateChannelOnIOThread()| creates a
+// channel synchronously and must be called from the I/O thread, while
+// |CreateChannel()| is asynchronous and may be called from any thread.
+// |DestroyChannel()| is used to destroy the channel in either case and may be
+// called from any thread, but completes synchronously when called from the I/O
+// 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.,
@@ -67,9 +69,8 @@ MOJO_SYSTEM_IMPL_EXPORT Configuration* GetConfiguration();
 
 // 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()| (or |DestoryChannel()|) to tear down the
-// channel. Returns a handle to the bootstrap message pipe.
+// the "out" value |*channel_info| should be passed to |DestoryChannel()| 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);
@@ -79,32 +80,25 @@ typedef base::Callback<void(ChannelInfo*)> DidCreateChannelCallback;
 // |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.
+// should eventually be passed to |DestroyChannel()| 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()|;
-// may be called from any thread. |channel_info| should be the value provided to
-// the callback to |CreateChannel()|.
+// Destroys a channel that was created using |CreateChannel()|; may be called

[yzshen1, 2014/11/13 22:48:32]

It seems nice if the comment also covers CreateChannelOnIOThread().

+// from any thread. |channel_info| should be the value provided to the callback
+// to |CreateChannel()|. If called from the I/O thread, this will complete
+// synchronously (in particular, it will post no tasks).
 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()|.
+// called before |DestroyChannel()|.
 MOJO_SYSTEM_IMPL_EXPORT void WillDestroyChannelSoon(ChannelInfo* channel_info);
 
 // Creates a |MojoHandle| that wraps the given |PlatformHandle| (taking