Fix process test and implementation after change to setter for registering event handler.

runtime/bin/process_impl.dart

Index: runtime/bin/process_impl.dart
diff --git a/runtime/bin/process_impl.dart b/runtime/bin/process_impl.dart
index 9dcff2a2f9e67a87749761b47ab660ec50273fc8..fdea9d7162e870c6fdadb21aead8934310646a03 100644
--- a/runtime/bin/process_impl.dart
+++ b/runtime/bin/process_impl.dart
@@ -57,7 +57,7 @@ class _Process implements Process {
 
     // Setup an exit handler to handle internal cleanup and possible
     // callback when a process terminates.
-    _exitHandler.setDataHandler(() {
+    _exitHandler.dataHandler = () {
         final int EXIT_DATA_SIZE = 8;
         List<int> exitDataBuffer = new List<int>(EXIT_DATA_SIZE);
         InputStream input = _exitHandler.inputStream;
@@ -85,7 +85,7 @@ class _Process implements Process {
         }
 
         input.dataHandler = exitData;
-      });
+      };
   }
 
   bool _start(String path,