Library root fix for win

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 6015 matching lines @@
   }
   // TODO(vsm): This is not necessarily unique if '__' appears in a file name.
   var encodedSeparator = '__';
   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(encodedSeparator);
   } else if (isWithin(libraryRoot, uri.toFilePath())) {
-    qualifiedPath = uri.path
+    qualifiedPath = uri
+        .toFilePath()
         .substring(libraryRoot.length)

[jakemac, 2017/05/24 18:25:17]

Should we change this to use `path.relative` as well, or save that for later?

         .replaceAll(separator, encodedSeparator);
   } else {
     // We don't have a unique name.
     throw 'Invalid library root. $libraryRoot does not contain ${uri
         .toFilePath()}';
   }
   return pathToJSIdentifier(qualifiedPath);
 }
 
 /// Debugger friendly name for a Dart Library.
@@ skipping 80 matching lines @@
   if (targetIdentifier.staticElement is! PrefixElement) return false;
   var prefix = targetIdentifier.staticElement as PrefixElement;
 
   // The library the prefix is referring to must come from a deferred import.
   var containingLibrary = resolutionMap
       .elementDeclaredByCompilationUnit(target.root as CompilationUnit)
       .library;
   var imports = containingLibrary.getImportsWithPrefix(prefix);
   return imports.length == 1 && imports[0].isDeferred;
 }