Return RequestErrorCode.NO_INDEX_GENERATED for search/refactoring requests.

pkg/analysis_server/lib/src/server/driver.dart

Index: pkg/analysis_server/lib/src/server/driver.dart
diff --git a/pkg/analysis_server/lib/src/server/driver.dart b/pkg/analysis_server/lib/src/server/driver.dart
index f161c54eff7cac47494f5eb7a0d36e137ee9e05e..504589c8e1ee7d079488909bf5bfe3cc1c801e47 100644
--- a/pkg/analysis_server/lib/src/server/driver.dart
+++ b/pkg/analysis_server/lib/src/server/driver.dart
@@ -132,6 +132,11 @@ class Driver implements ServerStarter {
   static const String NO_ERROR_NOTIFICATION = "no-error-notification";
 
   /**
+   * The name of the flag used to disable the index.
+   */
+  static const String NO_INDEX = "no-index";
+
+  /**
    * The name of the option used to set the file read mode.
    */
   static const String FILE_READ_MODE = "file-read-mode";
@@ -218,6 +223,7 @@ class Driver implements ServerStarter {
     analysisServerOptions.enableIncrementalResolutionValidation =
         results[INCREMENTAL_RESOLUTION_VALIDATION];
     analysisServerOptions.noErrorNotification = results[NO_ERROR_NOTIFICATION];
+    analysisServerOptions.noIndex = results[NO_INDEX];
     analysisServerOptions.fileReadMode = results[FILE_READ_MODE];
 
     _initIncrementalLogger(results[INCREMENTAL_RESOLUTION_LOG]);
@@ -347,6 +353,11 @@ class Driver implements ServerStarter {
         help: "disable sending all analysis error notifications to the server",
         defaultsTo: false,
         negatable: false);
+    parser.addFlag(
+        NO_INDEX,
+        help: "disable indexing sources",
+        defaultsTo: false,
+        negatable: false);
     parser.addOption(
         FILE_READ_MODE,
         help: "an option of the ways files can be read from disk, " +