Support Package Resolution Configuration files.

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 'memory_source_file_helper.dart';
 
 import 'package:compiler/src/compile_time_constants.dart';
 
@@ skipping 92 matching lines @@
 
   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
-    // already (and will not attemp to read them again due to caching). These
+    // already (and will not attempt to read them again due to caching). These
     // files must be available to the new diagnostic handler.
     provider = expando[cachedCompiler.provider];
     readStringFromUri = cachedCompiler.provider;
     provider.memorySourceFiles = memorySourceFiles;
   }
   var handler =
       createDiagnosticHandler(diagnosticHandler, provider, showDiagnostics);
 
   EventSink<String> noOutputProvider(String name, String extension) {
     if (name != '') throw 'Attempt to output file "$name.$extension"';
@@ skipping 113 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);
 }