[compositorworker] Register compositor proxies with proxy client

third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html

Index: third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html
diff --git a/third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html b/third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html
index bd57b71b4f255acce0401a1c35b340ed967ecc3b..e41515763156119570d349318f804ba8c259383f 100644
--- a/third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html
+++ b/third_party/WebKit/LayoutTests/virtual/threaded/fast/compositorworker/compositor-proxy-postmessage.html
@@ -4,10 +4,11 @@
 <script src="../../../../resources/testharnessreport.js"></script>
 <script>
 
-var test = async_test("This test checks that an element's compositor proxy can be sent from the main thread to the compositor thread.");
+var test = async_test("This test checks that an element's compositor proxy can be sent from the main thread to the compositor thread and back again.");
 
 var lastAttribute = '';
-function checkResponse(opacity, transform) {
+function checkResponse(proxy, opacity, transform) {
+    assert_equals(typeof proxy, 'object');
     assert_true(opacity || transform);
     assert_not_equals(opacity, transform);
     var currentAttribute = opacity ? 'opacity' : 'transform';
@@ -21,15 +22,13 @@ function checkResponse(opacity, transform) {
 
 function processMessage(msg) {
     var message = msg.data;
-    assert_equals('response', message.type);
-    checkResponse(message.opacity, message.transform);
+    checkResponse(message.proxy, message.opacity, message.transform);
 }
 
 var first = new CompositorWorker('resources/proxy-echo.js');
 first.onmessage = processMessage;
 var proxy = new CompositorProxy(document.getElementById('container'), ['opacity']);
 assert_true(proxy.supports('opacity'));
-assert_false(proxy.supports('touch'));
 assert_false(proxy.supports('transform'));
 assert_false(proxy.supports('scrollTop'));
 first.postMessage(proxy);
@@ -39,7 +38,6 @@ second.onmessage = processMessage;
 proxy = new CompositorProxy(document.getElementById('container'), ['transform']);
 assert_true(proxy.supports('transform'));
 assert_false(proxy.supports('opacity'));
-assert_false(proxy.supports('touch'));
 assert_false(proxy.supports('scrollTop'));
 second.postMessage(proxy);