Remote Assistance on Chrome OS Part II - Native Messaging renaming

extensions/browser/api/messaging/native_messaging_channel.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 EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGING_CHANNEL_H_
+#define EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGING_CHANNEL_H_
+
+#include "base/callback.h"
+
+namespace base {
+class Value;
+}  // namespace base
+
+namespace extensions {
+
+// Defines an interface to read messages and send responses between a native

[Sergey Ulanov, 2014/09/18 18:08:35]

nit: "Defines an " is redundant. Just "Interface ...".
Also it can be used to send any messages, not just responses. I suggest this
wording: "Interface for sending and receiving messages on
NativeMessagingChannel. Channel is disconnected when NativeMessagingChannel is
destroyed." 

[kelvinp, 2014/09/18 19:03:50]

Done.

+// component and chrome.
+class NativeMessagingChannel {
+ public:
+  // Callback interface for the channel. EventHandler must be valid as long as
+  // NativeMessagingChannel is valid.

[Sergey Ulanov, 2014/09/18 18:08:35]

"valid" is ambiguous. Suggest rewording second sentence "EventHandler must
outlive NativeMessagingChannel."

[kelvinp, 2014/09/18 19:03:50]

Done.

+  class EventHandler {
+   public:
+    // Invoked when a message is received from the other endpoint.
+    virtual void OnMessage(scoped_ptr<base::Value> message) = 0;
+
+    // Invoked when there is an error in sending or receiving a message.

[Sergey Ulanov, 2014/09/18 18:08:35]

Suggest "Called when the channel is disconnected."

[kelvinp, 2014/09/18 19:03:50]

Done.

+    // The event handler should shut down the channel on this event.

[Sergey Ulanov, 2014/09/18 18:08:35]

It's not clear what this means. Does it mean that the handler has to delete the
calling NativeMessagingChannel? Maybe "EventHandler is guaranteed not to called
after OnDisconnect()."?

[kelvinp, 2014/09/18 19:03:50]

Done.

+    virtual void OnDisconnect() = 0;
+
+    virtual ~EventHandler() {}
+  };
+
+  virtual ~NativeMessagingChannel() {}
+
+  // Starts reading and processing messages.
+  virtual void Start(EventHandler* event_handler) = 0;
+
+  // Sends a message to the other endpoint.
+  virtual void SendMessage(scoped_ptr<base::Value> message) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_MESSAGING_NATIVE_MESSAGING_CHANNEL_H_