Dart: Removes need to call listen().

mojo/public/dart/src/proxy.dart

Index: mojo/public/dart/src/proxy.dart
diff --git a/mojo/public/dart/src/proxy.dart b/mojo/public/dart/src/proxy.dart
index 6b00cd793bba289504f84a44ac9ef54b09a704fc..36c297ffdbc21419c334fae96be6324035ffb860 100644
--- a/mojo/public/dart/src/proxy.dart
+++ b/mojo/public/dart/src/proxy.dart
@@ -8,15 +8,13 @@ abstract class Proxy extends core.MojoEventStreamListener {
   Map<int, Completer> _completerMap;
   int _nextId = 0;
 
-  Proxy.fromEndpoint(core.MojoMessagePipeEndpoint endpoint, {bool doListen:
-      true, Function onClosed})
+  Proxy.fromEndpoint(core.MojoMessagePipeEndpoint endpoint)
       : _completerMap = {},
-        super.fromEndpoint(endpoint, doListen: doListen, onClosed: onClosed);
+        super.fromEndpoint(endpoint);
 
-  Proxy.fromHandle(core.MojoHandle handle, {bool doListen: true,
-      Function onClosed})
+  Proxy.fromHandle(core.MojoHandle handle)
       : _completerMap = {},
-        super.fromHandle(handle, doListen: doListen, onClosed: onClosed);
+        super.fromHandle(handle);
 
   Proxy.unbound()
       : _completerMap = {},