Implement getRange (returning an Iterable).

sdk/lib/web_sql/dart2js/web_sql_dart2js.dart

 /**
  * An API for storing data in the browser that can be queried with SQL.
  *
  * **Caution:** this specification is no longer actively maintained by the Web
  * Applications Working Group and may be removed at any time.
  * See [the W3C Web SQL Database specification](http://www.w3.org/TR/webdatabase/)
  * for more information.
  *
  * The [dart:indexed_db] APIs is a recommended alternatives.
  */
@@ skipping 369 matching lines @@
   }
 
   void removeRange(int start, int rangeLength) {
     throw new UnsupportedError("Cannot removeRange on immutable List.");
   }
 
   void insertRange(int start, int rangeLength, [Map initialValue]) {
     throw new UnsupportedError("Cannot insertRange on immutable List.");
   }
 
+  Iterable<Map> getRange(int start, int end) =>
+    IterableMixinWorkaround.getRangeList(this, start, end);
+
   List<Map> sublist(int start, [int end]) {
     if (end == null) end = length;
     return Lists.getRange(this, start, end, <Map>[]);
   }
 
-  List<Map> getRange(int start, int rangeLength) =>
-      sublist(start, start + rangeLength);
-
   Map<int, Map> asMap() =>
     IterableMixinWorkaround.asMapList(this);
 
   String toString() {
     StringBuffer buffer = new StringBuffer('[');
     buffer.writeAll(this, ', ');
     buffer.write(']');
     return buffer.toString();
   }
 
@@ skipping 44 matching lines @@
 // BSD-style license that can be found in the LICENSE file.
 
 
 @DocsEditable
 @DomName('SQLTransactionSync')
 @SupportedBrowser(SupportedBrowser.CHROME)
 @SupportedBrowser(SupportedBrowser.SAFARI)
 @Experimental
 abstract class _SQLTransactionSync native "*SQLTransactionSync" {
 }