Revert "Fix library name insert and access inconsistency on windows"

pkg/dev_compiler/lib/src/compiler/code_generator.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.
 
 import 'dart:collection' show HashMap, HashSet;
 import 'dart:math' show min, max;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 13 matching lines @@
 import 'package:analyzer/src/summary/idl.dart' show UnlinkedUnit;
 import 'package:analyzer/src/summary/link.dart' as summary_link;
 import 'package:analyzer/src/summary/package_bundle_reader.dart';
 import 'package:analyzer/src/summary/summarize_ast.dart'
     show serializeAstUnlinked;
 import 'package:analyzer/src/summary/summarize_elements.dart'
     show PackageBundleAssembler;
 import 'package:analyzer/src/summary/summary_sdk.dart';
 import 'package:analyzer/src/task/strong/ast_properties.dart'
     show isDynamicInvoke, setIsDynamicInvoke, getImplicitAssignmentCast;
-import 'package:path/path.dart' show separator, isWithin, fromUri;
+import 'package:path/path.dart' show separator;
 
 import '../closure/closure_annotator.dart' show ClosureAnnotator;
 import '../js_ast/js_ast.dart' as JS;
 import '../js_ast/js_ast.dart' show js;
 import 'ast_builder.dart' show AstBuilder;
 import 'compiler.dart' show BuildUnit, CompilerOptions, JSModuleFile;
 import 'element_helpers.dart';
 import 'element_loader.dart' show ElementLoader;
 import 'extension_types.dart' show ExtensionTypeSet;
 import 'js_field_storage.dart' show checkForPropertyOverride, getSuperclasses;
@@ skipping 5400 matching lines @@
 /// Choose a canonical name from the [library] element.
 ///
 /// This never uses the library's name (the identifier in the `library`
 /// declaration) as it doesn't have any meaningful rules enforced.
 String jsLibraryName(String libraryRoot, LibraryElement library) {
   var uri = library.source.uri;
   if (uri.scheme == 'dart') {
     return uri.path;
   }
   // TODO(vsm): This is not necessarily unique if '__' appears in a file name.
-  var customSeparator = '__';
+  var separator = '__';
   String qualifiedPath;
   if (uri.scheme == 'package') {
     // Strip the package name.
     // TODO(vsm): This is not unique if an escaped '/'appears in a filename.
     // E.g., "foo/bar.dart" and "foo$47bar.dart" would collide.
-    qualifiedPath = uri.pathSegments.skip(1).join(customSeparator);
-  } else if (isWithin(libraryRoot, uri.toFilePath())) {
-    qualifiedPath = fromUri(uri)
-        .substring(libraryRoot.length)
-        .replaceAll(separator, customSeparator);
+    qualifiedPath = uri.pathSegments.skip(1).join(separator);
+  } else if (uri.toFilePath().startsWith(libraryRoot)) {
+    qualifiedPath =
+        uri.path.substring(libraryRoot.length).replaceAll('/', separator);
   } else {
     // We don't have a unique name.
     throw 'Invalid library root. $libraryRoot does not contain ${uri
         .toFilePath()}';
   }
   return pathToJSIdentifier(qualifiedPath);
 }
 
 /// Shorthand for identifier-like property names.
 /// For now, we emit them as strings and the printer restores them to
@@ skipping 21 matching lines @@
 }
 
 bool isLibraryPrefix(Expression node) =>
     node is SimpleIdentifier && node.staticElement is PrefixElement;
 
 LibraryElement _getLibrary(AnalysisContext c, String uri) =>
     c.computeLibraryElement(c.sourceFactory.forUri(uri));
 
 bool _isDartRuntime(LibraryElement l) =>
     l.isInSdk && l.source.uri.toString() == 'dart:_runtime';