remove unused cache arguments

pkg/analysis_server/lib/src/domain_completion.dart

Index: pkg/analysis_server/lib/src/domain_completion.dart
diff --git a/pkg/analysis_server/lib/src/domain_completion.dart b/pkg/analysis_server/lib/src/domain_completion.dart
index dc6cc9e183466acda31b8841250ecaf50a6a4fdd..1c8ece0135bb07c38296e7c683eaaf57e8e92c94 100644
--- a/pkg/analysis_server/lib/src/domain_completion.dart
+++ b/pkg/analysis_server/lib/src/domain_completion.dart
@@ -74,8 +74,7 @@ class CompletionDomainHandler implements RequestHandler {
       }
       _discardManager();
     }
-    _manager =
-        createCompletionManager(context, source, server.searchEngine, null);
+    _manager = createCompletionManager(context, source, server.searchEngine);
     if (context != null) {
       _sourcesChangedSubscription =
           context.onSourcesChanged.listen(sourcesChanged);
@@ -97,8 +96,8 @@ class CompletionDomainHandler implements RequestHandler {
   }
 
   CompletionManager createCompletionManager(AnalysisContext context,
-      Source source, SearchEngine searchEngine, CompletionCache cache) {
-    return new CompletionManager.create(context, source, searchEngine, cache);
+      Source source, SearchEngine searchEngine) {
+    return new CompletionManager.create(context, source, searchEngine);
   }
 
   @override