Remove the last external import in protocol.

pkg/analysis_server/lib/src/protocol.dart

 // Copyright (c) 2014, 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.
 
 library protocol;
 
 import 'dart:collection';
 import 'dart:convert';
 
-import 'package:analysis_server/src/services/json.dart';
-
 part 'generated_protocol.dart';
 
 
 final Map<String, RefactoringKind> REQUEST_ID_REFACTORING_KINDS =
     new HashMap<String, RefactoringKind>();
 
 /**
  * Translate the input [map], applying [keyCallback] to all its keys, and
  * [valueCallback] to all its values.
  */
@@ skipping 205 matching lines @@
 }
 
 
 /**
  * Type of callbacks used to decode parts of JSON objects.  [jsonPath] is a
  * string describing the part of the JSON object being decoded, and [value] is
  * the part to decode.
  */
 typedef Object JsonDecoderCallback(String jsonPath, Object value);
 
+
+/**
+ * Instances of the class [HasToJson] implement [toJson] method that returns
+ * a JSON presentation.
+ */
+abstract class HasToJson {
+  /**
+   * Returns a JSON presentation of the object.
+   */
+  Map<String, Object> toJson();
+}
+
+
 /**
  * Base class for decoding JSON objects.  The derived class must implement
  * error reporting logic.
  */
 abstract class JsonDecoder {
   /**
    * Create an exception to throw if the JSON object at [jsonPath] fails to
    * match the API definition of [expected].
    */
   dynamic mismatch(String jsonPath, String expected);
@@ skipping 576 matching lines @@
     hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
     hash = hash ^ (hash >> 11);
     return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
   }
 
   static int hash2(a, b) => finish(combine(combine(0, a), b));
 
   static int hash4(a, b, c, d) =>
       finish(combine(combine(combine(combine(0, a), b), c), d));
 }