Remove use of package:analyzer in dependency_grapher

pkg/front_end/lib/src/fasta/source/directive_listener.dart

Index: pkg/front_end/lib/src/fasta/source/directive_listener.dart
diff --git a/pkg/front_end/lib/src/fasta/source/directive_listener.dart b/pkg/front_end/lib/src/fasta/source/directive_listener.dart
new file mode 100644
index 0000000000000000000000000000000000000000..278b44a02bb6977e887a4ca222d5a215591b163c
--- /dev/null
+++ b/pkg/front_end/lib/src/fasta/source/directive_listener.dart
@@ -0,0 +1,88 @@
+// 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.
+
+/// Listener used in combination with `TopLevelParser` to extract the URIs of
+/// import, part, and export directives.
+library front_end.src.fasta.source.directive_listener;
+
+import '../fasta_codes.dart' show FastaMessage, codeExpectedBlockToSkip;
+import '../parser/dart_vm_native.dart' show skipNativeClause;
+import '../parser/listener.dart';
+import '../quote.dart';
+import '../scanner/token.dart';
+
+/// Listener that records the URIs from imports, exports, and part directives.
+///
+/// This is normally used in combination with the `TopLevelParser`, which skips
+/// over the body of declarations like classes and function that are irrelevant
+/// for directives. Note that on correct programs directives cannot occur after
+/// any top-level declaration, but we recommend to continue parsing the entire
+/// file in order to gracefully handle input errors.
+class DirectiveListener extends Listener {
+  /// Whether we accept the native-syntax used by the VM patch files.
+  final bool acceptsNativeClause;
+
+  /// Collects URIs that occur on any import directive.
+  final Set<String> imports = new Set<String>();
+
+  /// Collects URIs that occur on any export directive.
+  final Set<String> exports = new Set<String>();
+
+  /// Collects URIs that occur on any part directive.
+  final Set<String> parts = new Set<String>();
+
+  DirectiveListener({this.acceptsNativeClause: false});
+
+  /// Set when entering the context of a directive, null when the parser is not
+  /// looking at a directive.
+  Set<String> _current = null;
+
+  bool get _inDirective => _current != null;
+
+  @override
+  beginImport(_) {
+    _current = imports;
+  }
+
+  @override
+  beginExport(_) {
+    _current = exports;
+  }
+
+  @override
+  beginPart(_) {
+    _current = parts;
+  }
+
+  @override
+  endExport(export, semicolon) {
+    _current = null;
+  }
+
+  @override
+  endImport(import, deferred, asKeyword, semicolon) {
+    _current = null;
+  }
+
+  @override
+  endPart(part, semicolon) {
+    _current = null;
+  }
+
+  @override
+  void beginLiteralString(Token token) {
+    if (_inDirective) {
+      _current.add(unescapeString(token.lexeme));
+    }
+  }
+
+  @override
+  Token handleUnrecoverableError(Token token, FastaMessage message) {
+    if (acceptsNativeClause && message.code == codeExpectedBlockToSkip) {
+      Token recover = skipNativeClause(token);
+      if (recover != null) return recover;
+    }
+    return super.handleUnrecoverableError(token, message);
+  }
+}