Make getKeys, getValues getters (keys, values).

lib/compiler/implementation/dart_backend/renamer.dart

Index: lib/compiler/implementation/dart_backend/renamer.dart
diff --git a/lib/compiler/implementation/dart_backend/renamer.dart b/lib/compiler/implementation/dart_backend/renamer.dart
index 6c822d1abd6fc5b20e6d7d7235179bb2e8c57ec2..2f09a3fe5b70540e96582748e0b5797cfed09fcb 100644
--- a/lib/compiler/implementation/dart_backend/renamer.dart
+++ b/lib/compiler/implementation/dart_backend/renamer.dart
@@ -76,7 +76,7 @@ void renamePlaceholders(
   }
 
   sortedForEach(Map<Element, Dynamic> map, f) {
-    for (Element element in sortElements(map.getKeys())) {
+    for (Element element in sortElements(map.keys)) {
       f(element, map[element]);
     }
   }
@@ -112,7 +112,7 @@ void renamePlaceholders(
   if (compiler.enableMinification) {
     MinifyingGenerator generator = new MinifyingGenerator();
     Set<String> forbiddenIdentifiers = new Set<String>.from(['main']);
-    forbiddenIdentifiers.addAll(Keyword.keywords.getKeys());
+    forbiddenIdentifiers.addAll(Keyword.keywords.keys);
     forbiddenIdentifiers.addAll(fixedMemberNames);
     generateUniqueName = (_) =>
         generator.generate(forbiddenIdentifiers.contains);
@@ -120,14 +120,14 @@ void renamePlaceholders(
     Function renameElement = makeElementRenamer(rename, generateUniqueName);
 
     Set<String> allParameterIdentifiers = new Set<String>();
-    for (var functionScope in placeholderCollector.functionScopes.getValues()) {
+    for (var functionScope in placeholderCollector.functionScopes.values) {
       allParameterIdentifiers.addAll(functionScope.parameterIdentifiers);
     }
     // Build a sorted (by usage) list of local nodes that will be renamed to
     // the same identifier. So the top-used local variables in all functions
     // will be renamed first and will all share the same new identifier.
     List<Set<Node>> allSortedLocals = new List<Set<Node>>();
-    for (var functionScope in placeholderCollector.functionScopes.getValues()) {
+    for (var functionScope in placeholderCollector.functionScopes.values) {
       // Add current sorted local identifiers to the whole sorted list
       // of all local identifiers for all functions.
       List<LocalPlaceholder> currentSortedPlaceholders =