Fix strong mode warnings. R=jmesserly@google.com Review URL: https://codereview.chromium.org//1843303002 .

diff --git a/pkgs/pool/CHANGELOG.md b/pkgs/pool/CHANGELOG.md
index dc852aa..9ad86d0 100644
--- a/pkgs/pool/CHANGELOG.md
+++ b/pkgs/pool/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.2.2
+
+* Fix strong mode warnings and add generic method annotations.
+
 ## 1.2.1
 
 * Internal changes only.

diff --git a/pkgs/pool/lib/pool.dart b/pkgs/pool/lib/pool.dart
index 3279160..f7bfd82 100644
--- a/pkgs/pool/lib/pool.dart
+++ b/pkgs/pool/lib/pool.dart

@@ -106,16 +106,18 @@
   /// Future.
   ///
   /// The return value of [callback] is piped to the returned Future.
-  Future withResource(callback()) {
+  Future/*<T>*/ withResource/*<T>*/(/*=T*/ callback()) async {
     if (isClosed) {
       throw new StateError(
           "withResource() may not be called on a closed Pool.");
     }
 
-    // TODO(nweiz): Use async/await when sdk#23497 is fixed.
-    return request().then((resource) {
-      return new Future.sync(callback).whenComplete(resource.release);
-    });
+    var resource = await request();
+    try {
+      return await callback();
+    } finally {
+      resource.release();
+    }
   }
 
   /// Closes the pool so that no more resources are requested.
@@ -189,7 +191,7 @@
       _onReleaseCompleters.removeFirst().completeError(error, stackTrace);
     });
 
-    var completer = new Completer.sync();
+    var completer = new Completer<PoolResource>.sync();
     _onReleaseCompleters.add(completer);
     return completer.future;
   }

diff --git a/pkgs/pool/pubspec.yaml b/pkgs/pool/pubspec.yaml
index 9635620..314ac04 100644
--- a/pkgs/pool/pubspec.yaml
+++ b/pkgs/pool/pubspec.yaml

@@ -1,5 +1,5 @@
 name: pool
-version: 1.2.1
+version: 1.2.2
 author: Dart Team <misc@dartlang.org>
 description: A class for managing a finite pool of resources.
 homepage: https://github.com/dart-lang/pool

diff --git a/pkgs/pool/test/pool_test.dart b/pkgs/pool/test/pool_test.dart
index 65fd00e..91e6833 100644
--- a/pkgs/pool/test/pool_test.dart
+++ b/pkgs/pool/test/pool_test.dart

@@ -276,7 +276,7 @@
     test("disallows request() and withResource()", () {
       var pool = new Pool(1)..close();
       expect(pool.request, throwsStateError);
-      expect(() => pool.withResource(() {}), throwsStateError);
+      expect(pool.withResource(() {}), throwsStateError);
     });
 
     test("pending requests are fulfilled", () async {