Add support for specifying files needing analysis

pkg/analysis_server/lib/plugin/fix.dart

Index: pkg/analysis_server/lib/plugin/fix.dart
diff --git a/pkg/analysis_server/lib/plugin/fix.dart b/pkg/analysis_server/lib/plugin/fix.dart
index 80456245cb68d93519f8472e01a32f8939ba02b6..45f69a6c99b4f4efc6642adc6a8ac414965a6e7c 100644
--- a/pkg/analysis_server/lib/plugin/fix.dart
+++ b/pkg/analysis_server/lib/plugin/fix.dart
@@ -13,9 +13,8 @@ import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:plugin/plugin.dart';
 
 /**
- * The identifier of the extension point that allows plugins to register new
- * fix contributors with the server. The object used as an extension must be a
- * [FixContributor].
+ * The identifier of the extension point that allows plugins to register fix
+ * contributors. The object used as an extension must be a [FixContributor].
  */
 final String FIX_CONTRIBUTOR_EXTENSION_POINT_ID = Plugin.join(
     ServerPlugin.UNIQUE_IDENTIFIER,