Update Timer API to take the callback as the last parameter.

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 72adf34de78f394236ed4b0be9bd3e8c18200089..2fcdaabfc2ee5e64eb688fccdb64edf1c459a5f0 100644
--- a/runtime/bin/process_impl.dart
+++ b/runtime/bin/process_impl.dart
@@ -47,7 +47,7 @@ class _Process implements Process {
     _onExit = null;
     // TODO(ager): Make the actual process starting really async instead of
     // simulating it with a timer.
-    new Timer((Timer ignore) => start(), 0);
+    new Timer(0, (Timer ignore) => start());
   }
 
   int _intFromBytes(List<int> bytes, int offset) {