Rename the global inference task and reduce it's API surface by introducing the

tests/compiler/dart2js/list_tracer2_test.dart

Index: tests/compiler/dart2js/list_tracer2_test.dart
diff --git a/tests/compiler/dart2js/list_tracer2_test.dart b/tests/compiler/dart2js/list_tracer2_test.dart
index 76ee4b5ae4edb09a7c445ebe6b486fc40445148d..040ffb200c72518e82b3dd1c0c6d56a8d1273a60 100644
--- a/tests/compiler/dart2js/list_tracer2_test.dart
+++ b/tests/compiler/dart2js/list_tracer2_test.dart
@@ -25,7 +25,7 @@ void main() {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
   asyncTest(() => compiler.run(uri).then((_) {
-    var typesInferrer = compiler.typesTask.typesInferrer;
+    var typesInferrer = compiler.globalInference.typesInferrer;
 
     checkType(String name, type) {
       var element = findElement(compiler, name);
@@ -33,6 +33,6 @@ void main() {
       Expect.equals(type, simplify(mask.elementType, compiler), name);
     }
 
-    checkType('myList', compiler.typesTask.uint31Type);
+    checkType('myList', compiler.commonMasks.uint31Type);
   }));
 }