Use Element instead of Symbol.

compiler/java/com/google/dart/compiler/ast/LibraryUnit.java

 // Copyright (c) 2011, 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.
 
 package com.google.dart.compiler.ast;
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.dart.compiler.DartCompiler;
 import com.google.dart.compiler.DartCompilerContext;
@@ skipping 55 matching lines @@
     element = Elements.libraryElement(this);
 
     // get the name part of the path, since it needs to be relative
     // TODO(jbrosenberg): change this to use lazy init
     // Note: We don't want an encoded relative path.
     String self = libSource.getUri().getSchemeSpecificPart();
     int lastSlash;
     if ((lastSlash = self.lastIndexOf('/')) > -1) {
       self = self.substring(lastSlash + 1);
     }
-    selfSourcePath = new LibraryNode(self); 
+    selfSourcePath = new LibraryNode(self);
   }
 
   public void addImportPath(LibraryNode path) {
     assert path != null;
     importPaths.add(path);
   }
 
   public void addSourcePath(LibraryNode path) {
     assert path != null;
     sourcePaths.add(path);
@@ skipping 79 matching lines @@
   /**
    * Return all prefixes used by this library.
    */
   public Set<String> getPrefixes() {
     return new HashSet<String>(prefixes.values());
   }
 
   /**
    * Return the path for dart source that corresponds to the same dart file as
    * this library unit. This is added to the set of sourcePaths for this unit.
-   * 
+   *
    * @return the self source path for this unit.
    */
   public LibraryNode getSelfSourcePath() {
     return selfSourcePath;
   }
 
   /**
    * Answer the source associated with this unit
    *
    * @return the library source (not <code>null</code>)
@@ skipping 72 matching lines @@
 
   /**
    * Writes this library's associated dependencies.
    */
   public void writeDeps(DartCompilerContext context) throws IOException {
     Writer writer = context.getArtifactWriter(libSource, "", DartCompiler.EXTENSION_DEPS);
     deps.write(writer);
     writer.close();
   }
 }