[analysis_server] Update some tests to work with normalized line endings

See #60234

Change-Id: I50f7973bd0fd989cadfa221813b0ea9904a5c5fe
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/423802
Reviewed-by: Samuel Rawlins <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: DanTup

pkg/analysis_server/test/src/computer/outline_computer_test.dart

@@ -29,8 +29,8 @@ class AbstractOutlineComputerTest extends AbstractContextTest {
   }
 
   Future<Outline> _computeOutline(String code) async {
-    testCode = code;
-    newFile(testPath, code);
+    testCode = normalizeSource(code);
+    newFile(testPath, testCode);
     var resolveResult = await getResolvedUnit(testFile);
     return DartUnitOutlineComputer(
       resolveResult,
@@ -48,8 +48,6 @@ class FlutterOutlineComputerTest extends AbstractOutlineComputerTest {
   }
 
   Future<void> test_columnWithChildren() async {
-    useLineEndingsForPlatform = false;
-
     var unitOutline = await _computeOutline('''
 import 'package:flutter/widgets.dart';