Merge the two buffer list implementations

runtime/bin/socket_stream.dart

Index: runtime/bin/socket_stream.dart
diff --git a/runtime/bin/socket_stream.dart b/runtime/bin/socket_stream.dart
index 4dfa6e38f31535197cc136d419fc8ad381305de9..e3d0d725a3fae66337efbfd6e6965932ad4a6034 100644
--- a/runtime/bin/socket_stream.dart
+++ b/runtime/bin/socket_stream.dart
@@ -54,55 +54,9 @@ class SocketInputStream implements InputStream {
 }
 
 
-class _BufferList2 {
-  _BufferList2() {
-    clear();
-  }
-
-  // Adds a new buffer to the list possibly with an offset of the
-  // first byte of interest. The offset can only be specified if the
-  // buffer list is empty.
-  void add(List<int> buffer, [int offset = 0]) {
-    assert(offset == 0 || _buffers.isEmpty());
-    _buffers.addLast(buffer);
-    _length += buffer.length - offset;
-    if (offset != 0) _index = offset;
-  }
-
-  List<int> get first() => _buffers.first();
-  int get index() => _index;
-
-  void removeBytes(int count) {
-    int firstRemaining = first.length - _index;
-    assert(count <= firstRemaining);
-    if (count == firstRemaining) {
-      _buffers.removeFirst();
-      _index = 0;
-    } else {
-      _index += count;
-    }
-    _length -= count;
-  }
-
-  int get length() => _length;
-
-  bool isEmpty() => _buffers.isEmpty();
-
-  void clear() {
-    _index = 0;
-    _length = 0;
-    _buffers = new Queue();
-  }
-
-  int _length;  // Total length of pending data.
-  Queue<List<int>> _buffers;
-  int _index;  // Offset into the first buffer of next write position.
-}
-
-
 class SocketOutputStream implements OutputStream {
   SocketOutputStream(Socket socket)
-      : _socket = socket, _pendingWrites = new _BufferList2() {
+      : _socket = socket, _pendingWrites = new _BufferList() {
     _socket.writeHandler = _writeHandler;
     _socket.errorHandler = _errorHandler;
   }
@@ -199,7 +153,7 @@ class SocketOutputStream implements OutputStream {
   }
 
   Socket _socket;
-  _BufferList2 _pendingWrites;
+  _BufferList _pendingWrites;
   var _noPendingWriteHandler;
   var _streamErrorHandler;
   bool _closing = false;