move functional argument check into manager

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

 // Copyright (c) 2015, 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 services.completion.dart.manager;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart'
@@ skipping 213 matching lines @@
       }
     } else {
       libSource = source;
     }
 
     // Most (all?) contributors need declarations in scope to be resolved
     if (libSource != null) {
       unit = await new AnalysisFutureHelper<CompilationUnit>(context,
               new LibrarySpecificUnit(libSource, source), RESOLVED_UNIT3)
           .computeAsync();
+
     }
 
-    return new DartCompletionRequestImpl._(
+    DartCompletionRequestImpl dartRequest = new DartCompletionRequestImpl._(
         request.context,
         request.resourceProvider,
         request.searchEngine,
         libSource,
         request.source,
         request.offset,
         unit);
+
+    // Resolve the expression in which the completion occurs
+    // to properly determine if identifiers should be suggested
+    // rather than invocations.
+    if (dartRequest.target.maybeFunctionalArgument()) {
+      AstNode node = dartRequest.target.containingNode.parent;
+      if (node is Expression) {
+        await dartRequest.resolveExpression(node);
+      }
+    }
+
+    return dartRequest;
   }
 }