Add ImportElement and ExportElement

pkg/compiler/lib/src/js_backend/namer.dart

Index: pkg/compiler/lib/src/js_backend/namer.dart
diff --git a/pkg/compiler/lib/src/js_backend/namer.dart b/pkg/compiler/lib/src/js_backend/namer.dart
index 6156b277c2107c48dd750947b0bb977e9ad7b05a..541aa7b1b3fbfe3ddf29a745bf0b4628d339b962 100644
--- a/pkg/compiler/lib/src/js_backend/namer.dart
+++ b/pkg/compiler/lib/src/js_backend/namer.dart
@@ -1144,12 +1144,12 @@ class Namer {
       LibraryElement library = element;
       name = libraryLongNames[library];
       if (name != null) return name;
-      name = library.getLibraryOrScriptName();
+      name = library.libraryOrScriptName;
       if (name.contains('.')) {
         // For libraries that have a library tag, we use the last part
         // of the fully qualified name as their base name. For all other
         // libraries, we use the first part of their filename.
-        name = library.hasLibraryName()
+        name = library.hasLibraryName
             ? name.substring(name.lastIndexOf('.') + 1)
             : name.substring(0, name.indexOf('.'));
       }
@@ -1346,7 +1346,7 @@ class Namer {
       return 'P';
     }
     return userGlobalObjects[
-        library.getLibraryOrScriptName().hashCode % userGlobalObjects.length];
+        library.libraryOrScriptName.hashCode % userGlobalObjects.length];
   }
 
   jsAst.Name deriveLazyInitializerName(jsAst.Name name) {
@@ -1988,4 +1988,4 @@ enum NamingScope {
   global,
   instance,
   constant
-}
+}