Partial backport of analyzer async/await fixes to Java.

editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/resolver/HintCodeTest.java

 /*
  * Copyright (c) 2013, the Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
@@ skipping 45 matching lines @@
   }
 
   public void fail_isNotInt() throws Exception {
     Source source = addSource(createSource(//
     "var v = 1 is! int;"));
     resolve(source);
     assertErrors(source, HintCode.IS_NOT_INT);
     verify(source);
   }
 
+  public void fail_missingReturn_async() throws Exception {
+    // TODO(paulberry): Some async/await type checking has not yet been fully backported from dart.
+    // See dartbug.com/22252.
+    Source source = addSource(createSource(//
+        "import 'dart:async';",
+        "Future<int> f() async {}"));
+    resolve(source);
+    assertErrors(source, HintCode.MISSING_RETURN);
+    verify(source);
+  }
+
   public void fail_overrideEqualsButNotHashCode() throws Exception {
     Source source = addSource(createSource(//
         "class A {",
         "  bool operator ==(x) {}",
         "}"));
     resolve(source);
     assertErrors(source, HintCode.OVERRIDE_EQUALS_BUT_NOT_HASH_CODE);
     verify(source);
   }
 
@@ skipping 1299 matching lines @@
         "  n() {",
         "    var a = m(), b = m();",
         "  }",
         "}"));
     resolve(source);
     assertErrors(source, HintCode.USE_OF_VOID_RESULT, HintCode.USE_OF_VOID_RESULT);
     verify(source);
   }
 
 }