- Fix or simplify use of Platform.packageRoot.

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 'dart:async';
 
 import 'package:compiler/compiler.dart' show
     DiagnosticHandler;
@@ skipping 97 matching lines @@
      List<String> options: const <String>[],
      CompilerImpl cachedCompiler,
      bool showDiagnostics: true,
      Uri packageRoot,
      Uri packageConfig,
      PackagesDiscoveryProvider packagesDiscoveryProvider}) {
   Uri libraryRoot = Uri.base.resolve('sdk/');
   if (packageRoot == null &&
       packageConfig == null &&
       packagesDiscoveryProvider == null) {
-    packageRoot = Uri.base.resolveUri(Uri.parse(Platform.packageRoot));
+    packageRoot = Uri.base.resolve(Platform.packageRoot);
   }
 
   MemorySourceFileProvider provider;
   if (cachedCompiler == null) {
     provider = new MemorySourceFileProvider(memorySourceFiles);
     // Saving the provider in case we need it later for a cached compiler.
     expando[provider] = provider;
   } else {
     // When using a cached compiler, it has read a number of files from disk
     // already (and will not attempt to read them again due to caching). These
@@ skipping 144 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);
 }