cleanup dart code completion contributors

pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart

Index: pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart b/pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart
index 6ca579ff5049645c803814a7c7bb8127a62cb1b7..2af32d59aa373cd0b272803b5cd5ab4cced32612 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart
@@ -187,20 +187,10 @@ class ArgListContributor extends DartCompletionContributor {
 
     // Determine if the target is in an argument list
     // for a method or a constructor or an annotation
-    // and resolve the identifier
     SimpleIdentifier targetId = _getTargetId(request.target.containingNode);
     if (targetId == null) {
       return EMPTY_LIST;
     }
-
-    // Resolve the target expression to determine the arguments
-    await request.resolveContainingExpression(targetId);
-    // Gracefully degrade if the element could not be resolved
-    // e.g. target changed, completion aborted
-    targetId = _getTargetId(request.target.containingNode);
-    if (targetId == null) {
-      return EMPTY_LIST;
-    }
     Element elem = targetId.bestElement;
     if (elem == null) {
       return EMPTY_LIST;