Clean up (most) uses of Array. Still more to come in the VM corelib code base.

compiler/lib/implementation/string_buffer.dart

 // Copyright (c) 2011, 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.
 
 /**
  * The StringBuffer class is useful for concatenating strings
  * efficiently. Only on a call to [toString] are the strings
  * concatenated to a single String.
  */
 class StringBufferImpl implements StringBuffer {
@@ skipping 42 matching lines @@
    * Returns [this].
    */
   StringBuffer addCharCode(int charCode) {
     return add(new String.fromCharCodes([charCode]));
   }
 
   /**
    * Clears the string buffer. Returns [this].
    */
   StringBuffer clear() {
-    _buffer = new Array<String>();
+    _buffer = new List<String>();
     _length = 0;
     return this;
   }
 
   /**
    * Returns the contents of buffer as a concatenated string.
    */
   String toString() {
     if (_buffer.length == 0) return "";
     if (_buffer.length == 1) return _buffer[0];
     String result = StringBase.concatAll(_buffer);
     _buffer.clear();
     _buffer.add(result);
     // Since we track the length at each add operation, there is no
     // need to update it in this function.
     return result;
   }
 
-  Array<String> _buffer;
+  List<String> _buffer;
   int _length;
 }