Remove upper case constants (#56) Remove usage of upper-case constants.

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc79f29..08c8734 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 2.0.7
 
 * Fix Dart 2 runtime errors.
+* Stop using deprecated constants from the SDK.
 
 ## 2.0.6
 

diff --git a/lib/src/async_cache.dart b/lib/src/async_cache.dart
index af52cd0..8c25267 100644
--- a/lib/src/async_cache.dart
+++ b/lib/src/async_cache.dart

@@ -42,7 +42,7 @@
   /// An ephemeral cache guarantees that a callback function will only be
   /// executed at most once concurrently. This is useful for requests for which
   /// data is updated frequently but stale data is acceptable.
-  factory AsyncCache.ephemeral() => new AsyncCache(Duration.ZERO);
+  factory AsyncCache.ephemeral() => new AsyncCache(Duration.zero);
 
   /// Creates a cache that invalidates its contents after [duration] has passed.
   ///

diff --git a/pubspec.yaml b/pubspec.yaml
index ae09136..e1ca801 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml

@@ -1,5 +1,5 @@
 name: async
-version: 2.0.7-dev
+version: 2.0.7
 author: Dart Team <misc@dartlang.org>
 description: Utility functions and classes related to the 'dart:async' library.
 homepage: https://www.github.com/dart-lang/async

diff --git a/test/stream_group_test.dart b/test/stream_group_test.dart
index 95eb8c1..d94f4d0 100644
--- a/test/stream_group_test.dart
+++ b/test/stream_group_test.dart

@@ -721,4 +721,4 @@
 }
 
 /// Wait for all microtasks to complete.
-Future flushMicrotasks() => new Future.delayed(Duration.ZERO);
+Future flushMicrotasks() => new Future.delayed(Duration.zero);

diff --git a/test/stream_splitter_test.dart b/test/stream_splitter_test.dart
index 68a6b74..70266ee 100644
--- a/test/stream_splitter_test.dart
+++ b/test/stream_splitter_test.dart

@@ -289,4 +289,4 @@
 }
 
 /// Wait for all microtasks to complete.
-Future flushMicrotasks() => new Future.delayed(Duration.ZERO);
+Future flushMicrotasks() => new Future.delayed(Duration.zero);

diff --git a/test/typed_wrapper/future_test.dart b/test/typed_wrapper/future_test.dart
index 0c8b00a..7fb91c8 100644
--- a/test/typed_wrapper/future_test.dart
+++ b/test/typed_wrapper/future_test.dart

@@ -61,12 +61,12 @@
 
       expect(
           new TypeSafeFuture<int>(new Completer<Object>().future)
-              .timeout(Duration.ZERO),
+              .timeout(Duration.zero),
           throwsA(new isInstanceOf<TimeoutException>()));
 
       expect(
           new TypeSafeFuture<int>(new Completer<Object>().future)
-              .timeout(Duration.ZERO, onTimeout: expectAsync0(() => 15)),
+              .timeout(Duration.zero, onTimeout: expectAsync0(() => 15)),
           completion(equals(15)));
     });
   });
@@ -100,7 +100,7 @@
 
         expect(
             new TypeSafeFuture<int>(new Completer<Object>().future)
-                .timeout(Duration.ZERO, onTimeout: expectAsync0(() => "foo"))
+                .timeout(Duration.zero, onTimeout: expectAsync0(() => "foo"))
                 .then((_) {}),
             throwsCastError);
       });

diff --git a/test/utils.dart b/test/utils.dart
index 9270886..39df0f6 100644
--- a/test/utils.dart
+++ b/test/utils.dart

@@ -9,7 +9,7 @@
 import "package:test/test.dart";
 
 /// A zero-millisecond timer should wait until after all microtasks.
-Future flushMicrotasks() => new Future.delayed(Duration.ZERO);
+Future flushMicrotasks() => new Future.delayed(Duration.zero);
 
 typedef void OptionalArgAction([a, b]);