Remove unused import

Change-Id: I62634bf7fd893d501adcf38d3835912738dee8ab
Reviewed-on: https://dart-review.googlesource.com/c/79466
Commit-Queue: Paul Berry <paulberry@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Auto-Submit: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

Author: stereotype441

pkg/analyzer/lib/src/task/dart.dart

@@ -22,7 +22,6 @@ import 'package:analyzer/src/dart/constant/constant_verifier.dart';
 import 'package:analyzer/src/dart/element/builder.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/inheritance_manager2.dart';
-import 'package:analyzer/src/dart/resolver/inheritance_manager.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/dart/sdk/patch.dart';