flag to limit file and package URI completion suggestions

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 8691f9b0ac11938bf29c255bc41560116445f740..d0c8380e78d017400f50e31614a673b184fc6ae1 100644
--- a/pkg/analysis_server/lib/src/server/driver.dart
+++ b/pkg/analysis_server/lib/src/server/driver.dart
@@ -12,6 +12,8 @@ import 'package:analysis_server/src/provisional/completion/dart/completion_plugi
 import 'package:analysis_server/src/server/diagnostic_server.dart';
 import 'package:analysis_server/src/server/http_server.dart';
 import 'package:analysis_server/src/server/stdio_server.dart';
+import 'package:analysis_server/src/services/completion/dart/uri_contributor.dart'
+    show UriContributor;
 import 'package:analysis_server/src/socket_server.dart';
 import 'package:analysis_server/starter.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
@@ -186,6 +188,11 @@ class Driver implements ServerStarter {
    */
   static const String CLIENT_VERSION = "client-version";
 
+  /**
+   * The name of the option used to enable DartPad specific functionality.
+   */
+  static const String DARTPAD_OPTION = "dartpad";
+
   /**
    * The name of the option used to enable instrumentation.
    */
@@ -334,6 +341,10 @@ class Driver implements ServerStarter {
       return null;
     }
 
+    if (results[DARTPAD_OPTION]) {
+      UriContributor.suggestFilePaths = false;
+    }
+
     if (results[HELP_OPTION]) {
       _printUsage(parser.parser, analytics, fromHelp: true);
       return null;
@@ -482,6 +493,10 @@ class Driver implements ServerStarter {
     parser.addOption(CLIENT_ID,
         help: "an identifier used to identify the client");
     parser.addOption(CLIENT_VERSION, help: "the version of the client");
+    parser.addFlag(DARTPAD_OPTION,
+        help: 'enable DartPad specific functionality',
+        defaultsTo: false,
+        hide: true);
     parser.addFlag(ENABLE_INSTRUMENTATION_OPTION,
         help: "enable sending instrumentation information to a server",
         defaultsTo: false,