Add ImportElement and ExportElement

pkg/compiler/lib/src/elements/common.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.
 
 /// Mixins that implement convenience methods on [Element] subclasses.
 
 library elements.common;
 
 import '../common/names.dart' show
     Names,
@@ skipping 115 matching lines @@
   @override
   bool get isPlatformLibrary => canonicalUri.scheme == 'dart';
 
   @override
   bool get isPackageLibrary => canonicalUri.scheme == 'package';
 
   @override
   bool get isInternalLibrary =>
       isPlatformLibrary && canonicalUri.path.startsWith('_');
 
-  String getLibraryOrScriptName() {
-    if (hasLibraryName()) {
-      return getLibraryName();
+  String get libraryOrScriptName {
+    if (hasLibraryName) {
+      return libraryName;
     } else {
       // Use the file name as script name.
       String path = canonicalUri.path;
       return path.substring(path.lastIndexOf('/') + 1);
     }
   }
 
   int compareTo(LibraryElement other) {
     if (this == other) return 0;
-    return getLibraryOrScriptName().compareTo(other.getLibraryOrScriptName());
+    return libraryOrScriptName.compareTo(other.libraryOrScriptName);
   }
 }
 
 abstract class CompilationUnitElementCommon implements CompilationUnitElement {
   int compareTo(CompilationUnitElement other) {
     if (this == other) return 0;
     return '${script.readableUri}'.compareTo('${other.script.readableUri}');
   }
 }
 
@@ skipping 331 matching lines @@
       // this signature must not have more required parameters.  Having more
       // optional parameters is not a problem, they simply are never provided
       // by call sites of a call to a method with the other signature.
       int otherTotalCount = signature.parameterCount;
       return requiredParameterCount <= otherTotalCount
           && parameterCount >= otherTotalCount;
     }
     return true;
   }
 }