Add support for fixes

pkg/analyzer_plugin/lib/src/utilities/fixes/fixes.dart

+// Copyright (c) 2017, 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.
+
+import 'package:analyzer/dart/analysis/results.dart';
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer_plugin/protocol/protocol_generated.dart';
+import 'package:analyzer_plugin/utilities/analyzer_converter.dart';
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
+
+/**
+ * A concrete implementation of [FixCollector].
+ */
+class FixCollectorImpl implements FixCollector {
+  /**
+   * The list of fixes that have been collected.
+   */
+  final Map<AnalysisError, List<PrioritizedSourceChange>> fixMap =
+      <AnalysisError, List<PrioritizedSourceChange>>{};
+
+  /**
+   * Return the fixes that have been collected up to this point.
+   */
+  List<AnalysisErrorFixes> get fixes {
+    List<AnalysisErrorFixes> fixes = <AnalysisErrorFixes>[];
+    AnalyzerConverter converter = new AnalyzerConverter();
+    for (AnalysisError error in fixMap.keys) {
+      fixes.add(new AnalysisErrorFixes(converter.convertAnalysisError(error),
+          fixes: fixMap[error]));
+    }
+    return fixes;
+  }
+
+  @override
+  void addFix(AnalysisError error, PrioritizedSourceChange change) {
+    fixMap.putIfAbsent(error, () => <PrioritizedSourceChange>[]).add(change);
+  }
+}
+
+/**
+ * A concrete implementation of [FixesRequest].
+ */
+class FixesRequestImpl implements FixesRequest {
+  @override
+  AnalysisError error;
+
+  @override
+  final ResourceProvider resourceProvider;
+
+  @override
+  final int offset;
+
+  @override
+  final ResolveResult result;
+
+  /**
+   * Initialize a newly create request with the given data.
+   */
+  FixesRequestImpl(this.resourceProvider, this.offset, this.result);
+}