Add line starts into unlinked units.

pkg/analyzer/test/src/summary/summary_common.dart

 // 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 analyzer.test.src.summary.summary_common;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
@@ skipping 8641 matching lines @@
     // References to other parts should still be resolved.
     allowMissingFiles = true;
     addNamedSource('/bar.dart', 'part of my.lib; class C {}');
     serializeLibraryText(
         'library my.lib; part "foo.dart"; part "bar.dart"; C c;',
         allowErrors: true);
     checkTypeRef(findVariable('c').type, null, null, 'C',
         expectedTargetUnit: 2);
   }
 
+  test_lineStarts() {
+    String text = '''
+int foo;
+class Test {}
+
+int bar;'''
+        .replaceAll('\r\n', '\n');
+    serializeLibraryText(text);
+    expect(unlinkedUnits[0].lineStarts, [0, 9, 23, 24]);
+  }
+
   test_linked_reference_reuse() {
     if (skipFullyLinkedData) {
       return;
     }
     // When the reference for a linked type is the same as an explicitly
     // referenced type, the explicit reference should be re-used.
     addNamedSource('/a.dart', 'class C {}');
     addNamedSource('/b.dart', 'import "a.dart"; C f() => null;');
     serializeLibraryText(
         'import "a.dart"; import "b.dart"; C c1; final c2 = f();');
@@ skipping 1854 matching lines @@
 class _PrefixExpectation {
   final ReferenceKind kind;
   final String name;
   final String absoluteUri;
   final String relativeUri;
   final int numTypeParameters;
 
   _PrefixExpectation(this.kind, this.name,
       {this.absoluteUri, this.relativeUri, this.numTypeParameters: 0});
 }