Change List constructors.

sdk/lib/core/list.dart

Index: sdk/lib/core/list.dart
diff --git a/sdk/lib/core/list.dart b/sdk/lib/core/list.dart
index b4948a3c1680aa616a39f6b605ea2363296015cb..1c5eafb9acfc5b53ab6245f3df322a7bfc3b79f3 100644
--- a/sdk/lib/core/list.dart
+++ b/sdk/lib/core/list.dart
@@ -9,18 +9,24 @@
 interface List<E> extends Collection<E>, Sequence<E>
                   default _ListImpl<E> {
   /**
-   * Creates a list of the given [length].
-   *
-   * If no [length] argument is supplied an extendable list of
-   * length 0 is created.
-   *
-   * If a [length] argument is supplied, a fixed size list of that
-   * length is created.
+   * Creates an extendable list of the given [length].
    */
-  List([int length]);
+  List([int length = 0]);
 
   /**
-   * Creates a list with the elements of [other]. The order in
+   * Creates a fixed-sized list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  List.fixedLength(int length, {E fill: null});
+
+  /**
+   * Creates an extendable list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  List.filled(int length, E fill);
+
+  /**
+   * Creates an extandable list with the elements of [other]. The order in
    * the list will be the order provided by the iterator of [other].
    */
   List.from(Iterable<E> other);
@@ -179,9 +185,21 @@ class _ListImpl<E> {
   /**
    * Factory implementation of List().
    *
-   * Creates a list of the given [length].
+   * Creates an extendable list of the given [length].
+   */
+  external factory List([int length = 0]);
+
+  /**
+   * Creates a fixed-sized list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  external factory List.fixedLength(int length, {E fill: null});
+
+  /**
+   * Creates an extendable list of the given [length] where each entry is
+   * filled with [fill].
    */
-  external factory List([int length]);
+  external factory List.filled(int length, E fill);
 
   /**
    * Factory implementation of List.from().