Implement the close() API for Message ports

android_webview/common/aw_message_port_messages.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.
 
 // Multiply-included file, no traditional include guard.
 #include <vector>
 
 #include "base/basictypes.h"
 #include "ipc/ipc_message_macros.h"
 
@@ skipping 35 matching lines @@
 IPC_MESSAGE_ROUTED3(AwMessagePortMsg_WebToAppMessage,
                     int /* recipient message port id */,
                     base::string16 /* message */,
                     std::vector<int> /* sent message port_ids */)
 
 // Tells the renderer to convert the message from a String16
 // format to a WebSerializedScriptValue. This IPC is used for messages that
 // are outgoing from Webview to JS.
 // TODO(sgurun) when we start supporting other types, use a ListValue instead
 // of string16
-IPC_MESSAGE_ROUTED3(AwMessagePortMsg_AppToWebMessage,
+IPC_MESSAGE_ROUTED4(AwMessagePortMsg_AppToWebMessage,
                     int /* recipient message port id */,
                     base::string16 /* message */,
-                    std::vector<int> /* sent message port_ids */)
+                    std::vector<int> /* sent message port_ids */,
+                    bool /* whether to close the message port */)

[mnaganov (inactive), 2015/02/25 10:36:26]

As for the port closing message there is no actual data that needs to be
converted, wouldn't it be more logical to avoid using this message at all, and
instead have a special dedicated one? This should also make cleaner code that
sends and code that handles the close command. Probably, a comment will be
needed that we need to use message in order to synchronize with in-flight
conversion messages.

[sgurun-gerrit only, 2015/02/25 20:06:37]

I think a special IPC would also work and the code will be cleaner. 
On 2015/02/25 10:36:26, mnaganov (cr) wrote:

 
 //-----------------------------------------------------------------------------
 // These are messages sent from the renderer to the browser process.
 
 // Response to AwMessagePortMessage_WebToAppMessage
 IPC_MESSAGE_ROUTED3(AwMessagePortHostMsg_ConvertedWebToAppMessage,
                     int /* recipient message port id */,
                     base::ListValue /* converted message */,
                     std::vector<int> /* sent message port_ids */)
 
 // Response to AwMessagePortMessage_AppToWebMessage
-IPC_MESSAGE_ROUTED3(AwMessagePortHostMsg_ConvertedAppToWebMessage,
+IPC_MESSAGE_ROUTED4(AwMessagePortHostMsg_ConvertedAppToWebMessage,
                     int /* recipient message port id */,
                     base::string16 /* converted message */,
-                    std::vector<int> /* sent message port_ids */)
+                    std::vector<int> /* sent message port_ids */,
+                    bool /* whether to close the message port */)