Files services library: Add an "output stream" file impl helper class.

apps/moterm/moterm_driver.h

 // Copyright 2015 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.
 
 // |MotermDriver| is a class providing a |mojo.files.File| interface,
 // implementing termios-type features (e.g., line editing; TODO(vtl): lots to do
 // here), and appropriately processing bytes to/from the terminal (which gets
 // and sends "raw" data). In essence, this class includes what would
 // traditionally be called the terminal driver in a Unix kernel.
 
@@ skipping 21 matching lines @@
   // closed or otherwise "broken").
   class Client {
    public:
     // Called when we receive data (for the client to "display").
     // TODO(vtl): Maybe add a way to throttle (e.g., for the client to not
     // accept all the data).
     // TODO(vtl): It's "probably OK" to call |Detach()| from inside this method,
     // but not verified.
     virtual void OnDataReceived(const void* bytes, size_t num_bytes) = 0;
 
-    // Called when the terminal "file" is closed (via |Close()|. (The client may
-    // optionally call |Detach()| in response.)
+    // Called when the terminal "file" is closed (via |Close()|). (The client
+    // may optionally call |Detach()| in response.)
     virtual void OnClosed() = 0;
 
     // Called when this object is destroyed (which will happen if the other end
     // of the message pipe is closed). The client must not call |Detach()| in
     // response. (Obviously, this will only be called if the client has not
     // called |Detach()|.)
     virtual void OnDestroyed() = 0;
   };
 
   // Static factory method. |client| must either outlive us, or if not call
@@ skipping 114 matching lines @@
   // Output settings:
   // If true, will convert output CRs to CR-NL pairs.
   bool onlcr_;
 
   base::WeakPtrFactory<MotermDriver> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MotermDriver);
 };
 
 #endif  // APPS_MOTERM_MOTERM_DRIVER_H_