Experiment with new function-type syntax.

pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart

Index: pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart
diff --git a/pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart b/pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart
index 170d16d07dc0629a424fd435cec13c0faf30ba93..b444a40c707ac1f4ebc655a7ead06867ea9cc49c 100644
--- a/pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart
+++ b/pkg/compiler/lib/src/js_emitter/runtime_type_generator.dart
@@ -4,12 +4,6 @@
 
 part of dart2js.js_emitter;
 
-// Function signatures used in the generation of runtime type information.
-typedef void FunctionTypeSignatureEmitter(
-    Element method, FunctionType methodType);
-
-typedef void SubstitutionEmitter(Element element, {bool emitNull});
-
 class TypeTestProperties {
   /// The index of the function type into the metadata.
   ///
@@ -157,9 +151,10 @@ class RuntimeTypeGenerator {
    */
   void _generateIsTestsOn(
       ClassElement cls,
-      void generateIsTest(Element element),
-      FunctionTypeSignatureEmitter generateFunctionTypeSignature,
-      SubstitutionEmitter generateSubstitution,
+      (Element) -> void generateIsTest,
+      (Element method, FunctionType methodType) -> void
+          generateFunctionTypeSignature,
+      (Element, {bool emitNull}) -> void generateSubstitution,
       void emitTypeCheck(TypeCheck check)) {
     Setlet<Element> generated = new Setlet<Element>();
 
@@ -267,9 +262,10 @@ class RuntimeTypeGenerator {
    */
   void _generateInterfacesIsTests(
       ClassElement cls,
-      void generateIsTest(ClassElement element),
-      SubstitutionEmitter generateSubstitution,
+      ClassElement -> void generateIsTest,
+      (Element, {bool emitNull}) -> void generateSubstitution,
       Set<Element> alreadyGenerated) {
+
     void tryEmitTest(ClassElement check) {
       if (!alreadyGenerated.contains(check) && checkedClasses.contains(check)) {
         alreadyGenerated.add(check);