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

pkg/compiler/lib/src/parser/parser_task.dart

Index: pkg/compiler/lib/src/parser/parser_task.dart
diff --git a/pkg/compiler/lib/src/parser/parser_task.dart b/pkg/compiler/lib/src/parser/parser_task.dart
index a0e900a4a5c8030d984f2b70f22478d38f1d6c23..b9d89ef6f77437e71404a13c9544e26af0f3ec47 100644
--- a/pkg/compiler/lib/src/parser/parser_task.dart
+++ b/pkg/compiler/lib/src/parser/parser_task.dart
@@ -29,7 +29,7 @@ class ParserTask extends CompilerTask {
   String get name => 'Parser';
 
   Node parse(ElementX element) {
-    return measure(() => element.parseNode(compiler));
+    return measure(() => element.parseNode(compiler.parsing));
   }
 
   Node parseCompilationUnit(Token token) {