Add Resolution and Parsing interfaces for computeType, ensureResolved and parseNode.

pkg/compiler/lib/src/resolution/signatures.dart

Index: pkg/compiler/lib/src/resolution/signatures.dart
diff --git a/pkg/compiler/lib/src/resolution/signatures.dart b/pkg/compiler/lib/src/resolution/signatures.dart
index 858f9b565cd0b636a334e8651445c9ce8209480d..fa9c87e68e48fcf15d528f0df506b98ca5c7af1a 100644
--- a/pkg/compiler/lib/src/resolution/signatures.dart
+++ b/pkg/compiler/lib/src/resolution/signatures.dart
@@ -148,7 +148,7 @@ class SignatureResolver extends MappingVisitor<FormalElementX> {
         assert(invariant(currentDefinitions,
             link.head.asIdentifier() != null || link.head.asSend() != null));
         if (fieldElement != null) {
-          element.typeCache = fieldElement.computeType(compiler);
+          element.typeCache = fieldElement.computeType(resolution);
         } else {
           element.typeCache = const DynamicType();
         }