Rename "field" -> "accessor" in several type inference methods.

pkg/front_end/lib/src/fasta/type_inference/dependency_collector.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.md file.
 
 import 'package:front_end/src/fasta/type_inference/type_inference_engine.dart';
 import 'package:kernel/ast.dart' show Expression;
 
 /// Keeps track of state while determining whether an expression has an
 /// immediately evident type, and if so what its dependencies are.
 ///
 /// This class describes the interface for use by clients of type inference.
 /// The implementation is in [DependencyCollectorImpl].
 abstract class DependencyCollector {
   /// Collects any dependencies of [expression], and reports errors if the
   /// expression does not have an immediately evident type.
   void collectDependencies(Expression expression);
 }
 
 /// Generic implementation of [DependencyCollectorImpl].
 ///
 /// This class contains all of the implementation of [DependencyCollector] which
 /// can be expressed without the need to reference private data structures in
 /// the shadow hierarchy.
 abstract class DependencyCollectorImpl extends DependencyCollector {
-  List<FieldNode> dependencies = [];
+  List<AccessorNode> dependencies = [];
 
   bool isImmediatelyEvident = true;
 
-  void recordDependency(FieldNode fieldNode) {
-    dependencies.add(fieldNode);
+  void recordDependency(AccessorNode accessorNode) {
+    dependencies.add(accessorNode);
   }
 
   void recordNotImmediatelyEvident(int fileOffset) {
     isImmediatelyEvident = false;
     // TODO(paulberry): report an error.
   }
 }