Add interface versioning. Methods queryVersion and requireVersion.

mojo/public/js/router.js

Index: mojo/public/js/router.js
diff --git a/mojo/public/js/router.js b/mojo/public/js/router.js
index 9db122052196331adbad56f15bf60792d8c8e8ed..c823ed4875c636c84a909ab68d09e05ff43a89c2 100644
--- a/mojo/public/js/router.js
+++ b/mojo/public/js/router.js
@@ -8,13 +8,15 @@ define("mojo/public/js/router", [
   "mojo/public/js/core",
   "mojo/public/js/connector",
   "mojo/public/js/validator",
-], function(console, codec, core, connector, validator) {
+  "mojo/public/js/lib/control_message_handler",
+], function(console, codec, core, connector, validator, controlMessageHandler) {
 
   var Connector = connector.Connector;
   var MessageReader = codec.MessageReader;
   var Validator = validator.Validator;
+  var ControlMessageHandler = controlMessageHandler.ControlMessageHandler;
 
-  function Router(handle, connectorFactory) {
+  function Router(handle, interface_version, connectorFactory) {
     if (!core.isHandle(handle))
       throw new Error("Router constructor: Not a handle");
     if (connectorFactory === undefined)
@@ -27,6 +29,11 @@ define("mojo/public/js/router", [
     this.payloadValidators_ = [];
     this.testingController_ = null;
 
+    if (interface_version !== undefined) {
+      this.controlMsgHandler_ = new ControlMessageHandler(this,

[yzshen1, 2017/02/11 01:11:29]

It is preferred to use full name: Msg -> Message. Unless it is something
commonly used such as Url, Http.

[wangjimmy, 2017/02/13 20:43:07]

Done.

+        interface_version);

[yzshen1, 2017/02/11 01:11:29]

4 spaces. Please see:
https://google.github.io/styleguide/javascriptguide.xml?showone=Code_formatti...

[wangjimmy, 2017/02/13 20:43:07]

Done.

+    }
+
     this.connector_.setIncomingReceiver({
         accept: this.handleIncomingMessage_.bind(this),
     });
@@ -107,7 +114,10 @@ define("mojo/public/js/router", [
       return;
 
     if (message.expectsResponse()) {
-      if (this.incomingReceiver_) {
+      if (this.controlMsgHandler_ &&
+          controlMessageHandler.isControlMessage(message)) {

[yzshen1, 2017/02/11 01:11:29]

if the message is a control message but we don't have a control message handler,
we should not pass this message to incomingReceiver_, instead we should directly
go to tear down the pipe.

[wangjimmy, 2017/02/13 20:43:07]

Done.

+        this.controlMsgHandler_.acceptWithResponder(message, this);
+      } else if (this.incomingReceiver_) {
         this.incomingReceiver_.acceptWithResponder(message, this);
       } else {
         // If we receive a request expecting a response when the client is not
@@ -125,8 +135,15 @@ define("mojo/public/js/router", [
         console.log("Unexpected response with request ID: " + requestID);
       }
     } else {
-      if (this.incomingReceiver_)
+      if (this.controlMsgHandler_ &&
+          controlMessageHandler.isControlMessage(message)) {
+        var ok = this.controlMsgHandler_.accept(message);
+        if (!ok) {
+          this.close();
+        }
+      } else if (this.incomingReceiver_) {
         this.incomingReceiver_.accept(message);
+      }
     }
   };