Make direct calls to _nativeIndexedGetter in "get last" "get first" "get single" instead of calling…

sdk/lib/web_sql/dartium/web_sql_dartium.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  * **Caution:** this specification is no longer actively maintained by the Web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 214 matching lines @@
   // -- start List<Map> mixins.
   // Map is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
   Map get first {
     if (this.length > 0) {
-      return this[0];
+      return _nativeIndexedGetter(0);
     }
     throw new StateError("No elements");
   }
 
   Map get last {
     int len = this.length;
     if (len > 0) {
-      return this[len - 1];
+      return _nativeIndexedGetter(len - 1);
     }
     throw new StateError("No elements");
   }
 
   Map get single {
     int len = this.length;
     if (len == 1) {
-      return this[0];
+      return _nativeIndexedGetter(0);
     }
     if (len == 0) throw new StateError("No elements");
     throw new StateError("More than one element");
   }
 
   Map elementAt(int index) => this[index];
   // -- end List<Map> mixins.
 
   @DomName('SQLResultSetRowList.item')
   @DocsEditable()
@@ skipping 31 matching lines @@
 @DocsEditable()
 @DomName('SQLTransactionSync')
 @SupportedBrowser(SupportedBrowser.CHROME)
 @SupportedBrowser(SupportedBrowser.SAFARI)
 @Experimental()
 // http://www.w3.org/TR/webdatabase/#sqltransactionsync
 @Experimental() // deprecated
 abstract class _SQLTransactionSync extends NativeFieldWrapperClass1 {
 
 }