Add FunctionEntity.asyncMarker and refactor SourceInformationStrategy to avoid ResolvedAst

pkg/compiler/lib/src/io/start_end_information.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Source information system that maps spans of Dart AST nodes to spans of
 /// JavaScript nodes.
 
 library dart2js.source_information.start_end;
 
 import 'package:front_end/src/fasta/scanner.dart' show Token;
 
 import '../common.dart';
 import '../diagnostics/messages.dart' show MessageTemplate;
-import '../elements/elements.dart' show ResolvedAst, ResolvedAstKind;
+import '../elements/elements.dart'
+    show MemberElement, ResolvedAst, ResolvedAstKind;
 import '../js/js.dart' as js;
 import '../js/js_source_mapping.dart';
 import '../tree/tree.dart' show Node;
 import 'source_file.dart';
 import 'source_information.dart';
 
 /// Source information that contains start source position and optionally an
 /// end source position.
 class StartEndSourceInformation extends SourceInformation {
   @override
@@ skipping 80 matching lines @@
   String toString() {
     return _computeText('${startPosition.sourceUri}');
   }
 }
 
 class StartEndSourceInformationStrategy
     extends JavaScriptSourceInformationStrategy {
   const StartEndSourceInformationStrategy();
 
   @override
-  SourceInformationBuilder createBuilderForContext(ResolvedAst resolvedAst) {
-    return new StartEndSourceInformationBuilder(resolvedAst);
+  SourceInformationBuilder createBuilderForContext(MemberElement member) {
+    return new StartEndSourceInformationBuilder(member);
   }
 
   @override
   SourceInformationProcessor createProcessor(
       SourceMapperProvider provider, SourceInformationReader reader) {
     return new StartEndSourceInformationProcessor(provider, reader);
   }
 }
 
 class StartEndSourceInformationProcessor extends SourceInformationProcessor {
@@ skipping 58 matching lines @@
       }
     }
   }
 }
 
 /// [SourceInformationBuilder] that generates [PositionSourceInformation].
 class StartEndSourceInformationBuilder extends SourceInformationBuilder {
   final SourceFile sourceFile;
   final String name;
 
-  StartEndSourceInformationBuilder(ResolvedAst resolvedAst)
-      : sourceFile = computeSourceFile(resolvedAst),
-        name = computeElementNameForSourceMaps(resolvedAst.element);
+  StartEndSourceInformationBuilder(MemberElement member)
+      : sourceFile = computeSourceFile(member.resolvedAst),
+        name = computeElementNameForSourceMaps(member.resolvedAst.element);
 
-  SourceInformation buildDeclaration(ResolvedAst resolvedAst) {
-    return StartEndSourceInformation._computeSourceInformation(resolvedAst);
+  SourceInformation buildDeclaration(MemberElement member) {
+    return StartEndSourceInformation
+        ._computeSourceInformation(member.resolvedAst);
   }
 
   SourceLocation sourceFileLocationForToken(Token token) {
     SourceLocation location =
         new OffsetSourceLocation(sourceFile, token.charOffset, name);
     checkValidSourceFileLocation(location, sourceFile, token.charOffset);
     return location;
   }
 
   void checkValidSourceFileLocation(
@@ skipping 35 matching lines @@
 
   @override
   SourceInformation buildCall(Node receiver, Node call) {
     return buildGeneric(receiver);
   }
 
   @override
   SourceInformation buildIf(Node node) => buildGeneric(node);
 
   @override
-  SourceInformationBuilder forContext(ResolvedAst resolvedAst,
+  SourceInformationBuilder forContext(MemberElement member,
       {SourceInformation sourceInformation}) {
-    return new StartEndSourceInformationBuilder(resolvedAst);
+    return new StartEndSourceInformationBuilder(member);
   }
 }