Catch exceptions in refactorings and return them as a SERVER_ERROR.

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';
 
 part 'generated_protocol.dart';
@@ skipping 733 matching lines @@
   /**
    * Initialize a newly created instance to represent an error condition caused
    * by a malformed request.
    */
   Response.invalidRequestFormat()
       : this(
           '',
           error: new RequestError(RequestErrorCode.INVALID_REQUEST, 'Invalid request'));
 
   /**
+   * Initialize a newly created instance to represent the SERVER_ERROR error
+   * condition.
+   */
+  factory Response.serverError(Request request, exception, stackTrace) {
+    RequestError error =
+        new RequestError(RequestErrorCode.SERVER_ERROR, exception.toString());
+    if (stackTrace != null) {
+      error.stackTrace = stackTrace.toString();
+    }
+    return new Response(request.id, error: error);
+  }
+
+  /**
    * Initialize a newly created instance to represent the
    * SORT_MEMBERS_INVALID_FILE error condition.
    */
   Response.sortMembersInvalidFile(Request request)
       : this(
           request.id,
           error: new RequestError(
               RequestErrorCode.SORT_MEMBERS_INVALID_FILE,
               'Error during `edit.sortMembers`: invalid file.'));
 
@@ skipping 88 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));
 }