Clean up dart:io warnings/errors found by analyzer tests.

sdk/lib/io/buffer_list.dart

 // Copyright (c) 2012, 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.
 
 part of dart.io;
 
 /**
  * Utility class that can fast concatenate [List<int>]s of bytes. Use
  * [readBytes] to get the final buffer.
  */
 class _BufferList {
-  const int _INIT_SIZE = 1 * 1024;
+  static const int _INIT_SIZE = 1 * 1024;
 
   _BufferList() {
     clear();
   }
 
   int pow2roundup(int x) {
     --x;
     x |= x >> 1;
     x |= x >> 2;
     x |= x >> 4;
@@ skipping 68 matching lines @@
    * Clears the content of the buffer list.
    */
   void clear() {
     _length = 0;
     _buffer = null;
   }
 
   int _length;  // Total number of bytes in the buffer.
   Uint8List _buffer;  // Internal buffer.
 }