insert parameters when completing imported functions and inherited methods

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

Index: pkg/analysis_server/lib/src/services/completion/imported_computer.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/imported_computer.dart b/pkg/analysis_server/lib/src/services/completion/imported_computer.dart
index d76a2046ff3b0eea204cea60bc8ee2da54498311..edbdd8ee9f525da1033be51c0c93f274d9d12e96 100644
--- a/pkg/analysis_server/lib/src/services/completion/imported_computer.dart
+++ b/pkg/analysis_server/lib/src/services/completion/imported_computer.dart
@@ -54,7 +54,8 @@ class ImportedComputer extends DartCompletionComputer {
  * [_ImportedSuggestionBuilder] traverses the imports and builds suggestions
  * based upon imported elements.
  */
-class _ImportedSuggestionBuilder implements SuggestionBuilder {
+class _ImportedSuggestionBuilder extends ElementSuggestionBuilder implements
+    SuggestionBuilder {
   bool shouldWaitForLowPrioritySuggestions;
   final DartCompletionRequest request;
   final bool typesOnly;
@@ -66,6 +67,9 @@ class _ImportedSuggestionBuilder implements SuggestionBuilder {
     cache = request.cache;
   }
 
+  @override
+  CompletionSuggestionKind get kind => CompletionSuggestionKind.INVOCATION;
+
   /**
    * If the needed information is cached, then add suggestions and return `true`
    * else return `false` indicating that additional work is necessary.
@@ -114,9 +118,6 @@ class _ImportedSuggestionBuilder implements SuggestionBuilder {
           return;
         }
         if (elem is ExecutableElement) {
-          if (elem.isOperator) {
-            return;
-          }
           DartType returnType = elem.returnType;
           if (returnType != null && returnType.isVoid) {
             if (excludeVoidReturn) {
@@ -124,14 +125,8 @@ class _ImportedSuggestionBuilder implements SuggestionBuilder {
             }
           }
         }
-        if (elem.isSynthetic) {
-          if (elem is PropertyAccessorElement || elem is FieldElement) {
-            return;
-          }
-        }
       }
-      request.suggestions.add(
-          createElementSuggestion(elem, relevance: COMPLETION_RELEVANCE_DEFAULT));
+      addSuggestion(elem);
     });
   }