Add interface versioning. Methods queryVersion and requireVersion.

mojo/public/js/tests/interface_ptr_unittest.js

Index: mojo/public/js/tests/interface_ptr_unittest.js
diff --git a/mojo/public/js/tests/interface_ptr_unittest.js b/mojo/public/js/tests/interface_ptr_unittest.js
index 22e0d6f15f3db3e3d1291050cbb8b9bb8adc028a..950d2a38ea6ae10be76b17a4c439e348d7b04994 100644
--- a/mojo/public/js/tests/interface_ptr_unittest.js
+++ b/mojo/public/js/tests/interface_ptr_unittest.js
@@ -7,12 +7,14 @@ define([
     "mojo/public/js/bindings",
     "mojo/public/js/core",
     "mojo/public/interfaces/bindings/tests/math_calculator.mojom",
+    "mojo/public/interfaces/bindings/tests/sample_interfaces.mojom",
     "mojo/public/js/threading",
     "gc",
 ], function(expect,
             bindings,
             core,
             math,
+            sampleInterfaces,
             threading,
             gc) {
   testIsBound()
@@ -21,6 +23,7 @@ define([
       .then(testConnectionError)
       .then(testPassInterface)
       .then(testBindRawHandle)
+      .then(testQueryVersion)
       .then(function() {
     this.result = "PASS";
     gc.collectGarbage();  // should not crash
@@ -157,4 +160,16 @@ define([
 
     return promise;
   }
+
+  function testQueryVersion() {
+    var integerAccessorImpl = new sampleInterfaces.IntegerAccessorPtr();

[yzshen1, 2017/02/06 06:57:26]

This is not an "implementation". An implementation is what you use to provide
the service. You using the Binding class to connect an implementation with an
interface request. Here what you create is the interface pointer, i.e., the user
side. Please look at line 112 - 113 as an example. We could talk more in-person.
These basic concepts are pretty important.

[yzshen1, 2017/02/06 07:04:18]

Sorry, I meant to say "You should use the Binding class ..."

+    var request = bindings.makeRequest(integerAccessorImpl);

[yzshen1, 2017/02/06 06:57:26]

The problem is that you need to provide support for the receiving side to handle
the control message. You will need to do:
- implement equivalent of
mojo/public/cpp/bindings/lib/control_message_handler.h, whenever Router receives
a message, it needs to check whether it is a control message, if yes, it lets
the control message handler handles it instead.
- here in this test, you need to bind this |request| to an Binding.

+    expect(integerAccessorImpl.ptr.version).toBe(0);
+
+    return integerAccessorImpl.ptr.queryVersion().then(function(version) {
+      expect(version).toBe(3);
+      expect(integerAccessorImpl.ptr.version).toBe(3);
+    });
+  }
 });
+