create new Dart specific completion contributor extension point

pkg/analysis_server/lib/src/provisional/completion/completion_dart.dart

Index: pkg/analysis_server/lib/src/provisional/completion/completion_dart.dart
diff --git a/pkg/analysis_server/lib/src/provisional/completion/completion_dart.dart b/pkg/analysis_server/lib/src/provisional/completion/completion_dart.dart
deleted file mode 100644
index de3ae925241e44c29d9022a49edfaa2bd46ccaf8..0000000000000000000000000000000000000000
--- a/pkg/analysis_server/lib/src/provisional/completion/completion_dart.dart
+++ /dev/null
@@ -1,70 +0,0 @@
-// 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 analysis_server.src.provisional.completion.completion_dart;
-
-import 'dart:async';
-
-import 'package:analysis_server/plugin/protocol/protocol.dart';
-import 'package:analysis_server/src/provisional/completion/completion_core.dart';
-import 'package:analysis_server/src/provisional/completion/dart/completion_target.dart';
-import 'package:analyzer/src/generated/ast.dart';
-
-export 'package:analysis_server/src/provisional/completion/completion_core.dart'
-    show EMPTY_LIST;
-
-const int DART_RELEVANCE_COMMON_USAGE = 1200;
-const int DART_RELEVANCE_DEFAULT = 1000;
-const int DART_RELEVANCE_HIGH = 2000;
-const int DART_RELEVANCE_INHERITED_ACCESSOR = 1057;
-const int DART_RELEVANCE_INHERITED_FIELD = 1058;
-const int DART_RELEVANCE_INHERITED_METHOD = 1057;
-const int DART_RELEVANCE_KEYWORD = 1055;
-const int DART_RELEVANCE_LOCAL_ACCESSOR = 1057;
-const int DART_RELEVANCE_LOCAL_FIELD = 1058;
-const int DART_RELEVANCE_LOCAL_FUNCTION = 1056;
-const int DART_RELEVANCE_LOCAL_METHOD = 1057;
-const int DART_RELEVANCE_LOCAL_TOP_LEVEL_VARIABLE = 1056;
-const int DART_RELEVANCE_LOCAL_VARIABLE = 1059;
-const int DART_RELEVANCE_LOW = 500;
-const int DART_RELEVANCE_NAMED_PARAMETER = 1060;
-const int DART_RELEVANCE_PARAMETER = 1059;
-
-/**
- * An object used to produce completions
- * at a specific location within a Dart file.
- *
- * Clients may implement this class when implementing plugins.
- */
-abstract class DartCompletionContributor {
-  /**
-   * Return a [Future] that completes with a list of suggestions
-   * for the given completion [request].
-   */
-  Future<List<CompletionSuggestion>> computeSuggestions(
-      DartCompletionRequest request);
-}
-
-/**
- * The information about a requested list of completions within a Dart file.
- *
- * Clients may not extend, implement or mix-in this class.
- */
-abstract class DartCompletionRequest extends CompletionRequest {
-  /**
-   * Return the completion target.  This determines what part of the parse tree
-   * will receive the newly inserted text.
-   */
-  CompletionTarget get target;
-
-  /**
-   * Return a [Future] that completes with a compilation unit in which
-   * all declarations in all scopes containing [target] have been resolved.
-   * The [Future] may return `null` if the unit cannot be resolved
-   * (e.g. unlinked part file).
-   * Any information obtained from [target] prior to calling this method
-   * should be discarded as it may have changed.
-   */
-  Future<CompilationUnit> resolveDeclarationsInScope();
-}