Revert of Introduce InterfaceEndpointClient(IEC), InterfaceEndpointHandle and

third_party/WebKit/LayoutTests/mojo/connection.html

Index: third_party/WebKit/LayoutTests/mojo/connection.html
diff --git a/third_party/WebKit/LayoutTests/mojo/connection.html b/third_party/WebKit/LayoutTests/mojo/connection.html
index 1e41f471f2052f3a4b5b21766655a81cc9ae25c6..bf275bd904163114ac3064738591a8192e47db03 100644
--- a/third_party/WebKit/LayoutTests/mojo/connection.html
+++ b/third_party/WebKit/LayoutTests/mojo/connection.html
@@ -88,6 +88,17 @@
     var response = await provider.echoStrings("hello", "world");
     assert_equals(response.a, "hello");
     assert_equals(response.b, "world");
+
+    try {
+      core.readMessage = function() {
+        return { result: core.RESULT_UNKNOWN };
+      };
+      await provider.echoString("goodbye");
+      assert_unreachable();
+    } catch (e) {
+      assert_not_equals(e, null);
+    }
+
   }, 'request response');
 
   done();