Cleanup some unused code in some of the tests

pkg/analysis_server/test/abstract_single_unit.dart

Index: pkg/analysis_server/test/abstract_single_unit.dart
diff --git a/pkg/analysis_server/test/abstract_single_unit.dart b/pkg/analysis_server/test/abstract_single_unit.dart
index bc8fe5c102722cea5275c8cda9812753140a6ae6..30d66dd50cfa3f44667f78c50b2072368d29126e 100644
--- a/pkg/analysis_server/test/abstract_single_unit.dart
+++ b/pkg/analysis_server/test/abstract_single_unit.dart
@@ -7,6 +7,7 @@ import 'dart:async';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/dart/ast/utilities.dart';
 import 'package:analyzer/src/dart/error/hint_codes.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
@@ -96,25 +97,18 @@ class AbstractSingleUnitTest extends AbstractContextTest {
 
   Future<Null> resolveTestUnit(String code) async {
     addTestSource(code);
-    if (enableNewAnalysisDriver) {
-      var result = await driver.getResult(testFile);
-      testUnit = (result).unit;
-      if (verifyNoTestUnitErrors) {
-        expect(result.errors.where((AnalysisError error) {
-          return error.errorCode != HintCode.DEAD_CODE &&
-              error.errorCode != HintCode.UNUSED_CATCH_CLAUSE &&
-              error.errorCode != HintCode.UNUSED_CATCH_STACK &&
-              error.errorCode != HintCode.UNUSED_ELEMENT &&
-              error.errorCode != HintCode.UNUSED_FIELD &&
-              error.errorCode != HintCode.UNUSED_IMPORT &&
-              error.errorCode != HintCode.UNUSED_LOCAL_VARIABLE;
-        }), isEmpty);
-      }
-    } else {
-      testUnit = await resolveLibraryUnit(testSource);
-      if (verifyNoTestUnitErrors) {
-        expect(context.getErrors(testSource).errors, isEmpty);
-      }
+    AnalysisResult result = await driver.getResult(testFile);
+    testUnit = result.unit;
+    if (verifyNoTestUnitErrors) {
+      expect(result.errors.where((AnalysisError error) {
+        return error.errorCode != HintCode.DEAD_CODE &&
+            error.errorCode != HintCode.UNUSED_CATCH_CLAUSE &&
+            error.errorCode != HintCode.UNUSED_CATCH_STACK &&
+            error.errorCode != HintCode.UNUSED_ELEMENT &&
+            error.errorCode != HintCode.UNUSED_FIELD &&
+            error.errorCode != HintCode.UNUSED_IMPORT &&
+            error.errorCode != HintCode.UNUSED_LOCAL_VARIABLE;
+      }), isEmpty);
     }
     testUnitElement = testUnit.element;
     testLibraryElement = testUnitElement.library;