Allow use of [keys] from a map by using different bailout strategy.

tests/compiler/dart2js/map_tracer_keys_test.dart

Index: tests/compiler/dart2js/map_tracer_keys_test.dart
diff --git a/tests/compiler/dart2js/map_tracer_keys_test.dart b/tests/compiler/dart2js/map_tracer_keys_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..cec1c2999f11b1ad36f6e3895bb80b6986bccd24
--- /dev/null
+++ b/tests/compiler/dart2js/map_tracer_keys_test.dart
@@ -0,0 +1,78 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:expect/expect.dart';
+import "package:async_helper/async_helper.dart";
+import
+    '../../../sdk/lib/_internal/compiler/implementation/types/types.dart'
+    show ContainerTypeMask, TypeMask;
+
+import 'compiler_helper.dart';
+import 'parser_helper.dart';
+import 'type_mask_test_helper.dart';
+
+
+String generateTest(String key, String value, bool initial) {
+  return """
+double aDouble = 42.5;
+List aList = [42];
+
+consume(x) => x;
+
+main() {
+""" + (initial ?
+"""
+  var theMap = {'a': 2.2, 'b': 3.3, 'c': 4.4, $key: $value};
+""" :
+"""
+  var theMap = {'a': 2.2, 'b': 3.3, 'c': 4.4};
+  theMap[$key] = $value;
+""") +
+"""
+  for (var key in theMap.keys) {
+    aDouble = theMap[key];
+  }
+  // We have to reference it somewhere, so that it always gets resolved.
+  consume(aList);
+}
+""";
+}
+
+void main() {
+  // Test using keys without the list floating in
+  doTest();
+  // Test using keys with the list floating in as key
+  doTest(key: "aList", bail: true);
+  // Test using keys with the list floating in as value
+  doTest(value: "aList");
+  // And the above where we add the list as part of the map literal.
+  doTest(initial: true);
+  doTest(key: "aList", bail: true, initial: true);
+  doTest(value: "aList", initial: true);
+}
+
+void doTest({String key: "'d'", String value: "5.5", bool bail: false,
+             bool initial: false}) {
+  Uri uri = new Uri(scheme: 'source');
+  var compiler = compilerFor(generateTest(key, value, initial), uri,
+      expectedErrors: 0, expectedWarnings: 0);
+  asyncTest(() => compiler.runCompiler(uri).then((_) {
+    var typesTask = compiler.typesTask;
+    var typesInferrer = typesTask.typesInferrer;
+    var aDoubleType =
+        typesInferrer.getTypeOfElement(findElement(compiler, 'aDouble'));
+    var aListType =
+        typesInferrer.getTypeOfElement(findElement(compiler, 'aList'));
+
+    Expect.equals(aDoubleType, typesTask.doubleType);
+    Expect.isTrue(aListType is ContainerTypeMask);
+    ContainerTypeMask container = aListType;
+    TypeMask elementType = container.elementType;
+    if (bail) {
+      Expect.equals(elementType, typesTask.dynamicType);
+    } else {
+      Expect.equals(elementType, typesTask.uint31Type);
+    }
+  }));
+}