Reapply "Implement new model for class members." and "Implement new model for interface members."

sdk/lib/_internal/compiler/implementation/use_unused_api.dart

 // Copyright (c) 2012, 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.
 
 /// This file use methods that aren't used by dart2js.dart, but that we wish to
 /// keep anyway. This might be general API that isn't currently in use,
 /// debugging aids, or API only used for testing (see TODO below).
 
 library dart2js.use_unused_api;
 
 import 'dart2js.dart' as dart2js;
 
 import 'dart2jslib.dart' as dart2jslib;
 
 import 'tree/tree.dart' as tree;
 
 import 'util/util.dart' as util;
 
+import 'elements/elements.dart' as elements;
+
 import 'elements/visitor.dart' as elements_visitor;
 
 import 'js/js.dart' as js;
 
 import 'types/concrete_types_inferrer.dart' as concrete_types_inferrer;
 
 import 'colors.dart' as colors;
 
 import 'filenames.dart' as filenames;
 
@@ skipping 19 matching lines @@
   useElementVisitor(new ElementVisitor());
   useJs(new js.Program(null));
   useJs(new js.Blob(null));
   useJs(new js.NamedFunction(null, null));
   useConcreteTypesInferrer(null);
   useColor();
   useFilenames();
   useSsa(null);
   useCodeBuffer(null);
   usedByTests();
+  useElements(null, null);
 }
 
 void useConstant(dart2jslib.Constant constant, dart2jslib.ConstantSystem cs) {
   constant.isObject();
   cs.isBool(constant);
 }
 
 void useNode(tree.Node node) {
   node
     ..asBreakStatement()
@@ skipping 100 matching lines @@
 
 useCodeBuffer(dart2jslib.CodeBuffer buffer) {
   buffer.writeln();
 }
 
 usedByTests() {
   // TODO(ahe): We should try to avoid including API used only for tests. In
   // most cases, such API can be moved to a test library.
   dart2jslib.World world = null;
   dart2jslib.Compiler compiler = null;
+  compiler.currentlyInUserCode();
+  compiler.inUserCode(null);
   type_graph_inferrer.TypeGraphInferrer typeGraphInferrer = null;
   source_file_provider.SourceFileProvider sourceFileProvider = null;
   world.hasAnyUserDefinedGetter(null);
   compiler.importHelperLibrary(null);
   typeGraphInferrer.getCallersOf(null);
   dart_types.Types.sorted(null);
   new universe.TypedSelector.subclass(null, null);
   new universe.TypedSelector.subtype(null, null);
   new universe.TypedSelector.exact(null, null);
   sourceFileProvider.readStringFromUri(null);
 }
+
+useElements(elements.ClassElement e, elements.Name n) {
+  e.lookupClassMember(null);
+  e.lookupInterfaceMember(null);
+  n.isAccessibleFrom(null);
+}