Add mojo <--> net IO adapters.

mojo/public/c/system/data_pipe.h

Index: mojo/public/c/system/data_pipe.h
diff --git a/mojo/public/c/system/data_pipe.h b/mojo/public/c/system/data_pipe.h
index e4a15e968f91f81b43b07452961fe95e7608da64..5fe8172967497e0e8289b4a616ee1539f090ecc6 100644
--- a/mojo/public/c/system/data_pipe.h
+++ b/mojo/public/c/system/data_pipe.h
@@ -187,9 +187,10 @@ MOJO_SYSTEM_EXPORT MojoResult
 // that thread can then wait for |data_pipe_producer_handle| to become writable
 // again.
 //
-// Once the caller has finished writing data to |*buffer|, it should call
-// |MojoEndWriteData()| to specify the amount written and to complete the
-// two-phase write.
+// When |MojoBeginWriteData)_| returtns MOJO_RESULT_OK, and the caller has

[yzshen1, 2014/10/10 21:18:59]

nit: MojoBeginWriteData)_ -> MojoBeginWriteData()

+// finished writing data to |*buffer|, it should call |MojoEndWriteData()| to
+// specify the amount written and to complete the two-phase write.
+// |MojoEndWriteData()| need not be called for other return values.

[yzshen1, 2014/10/10 21:18:59]

need->needs

[brettw, 2014/10/10 22:36:59]

It seems correct to me.

 //
 // Note: If the data pipe has the "may discard" option flag (specified on
 // creation) and |flags| has |MOJO_WRITE_DATA_FLAG_ALL_OR_NONE| set, this may