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

tests/compiler/dart2js/memory_compiler.dart

 // Copyright (c) 2013, 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.
 
 library dart2js.test.memory_compiler;
 
-import 'package:expect/expect.dart';
 import 'memory_source_file_helper.dart';
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart'
        show NullSink;
+import '../../../sdk/lib/_internal/compiler/implementation/filenames.dart';
 
 import '../../../sdk/lib/_internal/compiler/compiler.dart'
        show Diagnostic, DiagnosticHandler;
 
 import 'dart:async';
 
 import '../../../sdk/lib/_internal/compiler/implementation/mirrors/mirrors.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart';
 
 class DiagnosticMessage {
@@ skipping 52 matching lines @@
   return handler;
 }
 
 Expando<MemorySourceFileProvider> expando =
     new Expando<MemorySourceFileProvider>();
 
 Compiler compilerFor(Map<String,String> memorySourceFiles,
                      {DiagnosticHandler diagnosticHandler,
                       List<String> options: const [],
                       Compiler cachedCompiler,
-                      bool showDiagnostics: true}) {
+                      bool showDiagnostics: true,
+                      Uri packageRoot}) {
   Uri script = currentDirectory.resolveUri(Platform.script);
   Uri libraryRoot = script.resolve('../../../sdk/');
-  Uri packageRoot = currentDirectory.resolve('${Platform.packageRoot}/');
+  if (packageRoot == null) {
+    packageRoot = currentDirectory.resolve(
+        appendSlash(nativeToUriPath(Platform.packageRoot)));
+  }
 
   MemorySourceFileProvider provider;
   var readStringFromUri;
   if (cachedCompiler == null) {
     provider = new MemorySourceFileProvider(memorySourceFiles);
     readStringFromUri = provider.readStringFromUri;
     // Saving the provider in case we need it later for a cached compiler.
     expando[readStringFromUri] = provider;
   } else {
     // When using a cached compiler, it has read a number of files from disk
@@ skipping 68 matching lines @@
       createDiagnosticHandler(diagnosticHandler, provider, showDiagnostics);
 
   List<Uri> libraries = <Uri>[];
   memorySourceFiles.forEach((String path, _) {
     libraries.add(new Uri(scheme: 'memory', path: path));
   });
 
   return analyze(libraries, libraryRoot, packageRoot,
                  provider, handler, options);
 }