Don't use kFSEventStreamCreateFlagNoDefer as it messes with event flushing.

BUG=
R=sgjesse@google.com

Review URL: https://codereview.chromium.org//321133002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@37171 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/pubspec.yaml b/pubspec.yaml
index a0e0ce4..adf8ddb 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -12,4 +12,4 @@
   scheduled_test: ">=0.9.3-dev <0.11.0"
   unittest: ">=0.9.2 <0.10.0"
 environment:
-  sdk: ">=1.3.0 <2.0.0"
+  sdk: ">=1.6.0 <2.0.0"