Delete dart_backend from compiler.

tests/compiler/dart2js/generate_code_with_compile_time_errors_test.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.
 
 // Test that the compiler can generates code with compile time error according
 // to the compiler options.
 
 library dart2js.test.generate_code_with_compile_time_errors;
 
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/compiler.dart';
-import 'package:compiler/src/dart_backend/dart_backend.dart';
 import 'package:compiler/src/js_backend/js_backend.dart';
 import 'memory_compiler.dart';
 import 'output_collector.dart';
 
 const MEMORY_SOURCE_FILES = const {
   'main.dart': ''' 
 foo() {
  const list = [];
 }
 
@@ skipping 22 matching lines @@
       collector.warnings.isEmpty,
       "Unexpected warnings: ${collector.warnings}");
   Expect.isFalse(
       collector.errors.isEmpty,
       "Expected compile-time errors.");
   Expect.equals(
       expectHint,
       collector.hints.isNotEmpty,
       "Unexpected hints: ${collector.warnings}");
 
-  bool isCodeGenerated;
-  if (options.contains('--output-type=dart')) {
-    DartBackend backend = compiler.backend;
-    isCodeGenerated = backend.outputter.libraryInfo != null;
-  } else {
-    JavaScriptBackend backend = compiler.backend;
-    isCodeGenerated = backend.generatedCode.isNotEmpty;
-  }
+  JavaScriptBackend backend = compiler.backend;
+  bool isCodeGenerated = backend.generatedCode.isNotEmpty;
   Expect.equals(
       expectedCodeGenerated,
       isCodeGenerated,
       expectedCodeGenerated
           ? "Expected generated code for options $options."
           : "Expected no code generated for options $options.");
   Expect.equals(
       expectedOutput,
       outputCollector.outputMap.isNotEmpty,
       expectedOutput
@@ skipping 33 matching lines @@
        expectedCodeGenerated: false,
        expectedOutput: false,
        expectHint: true);
     await test(
        ['--use-cps-ir',
         '--generate-code-with-compile-time-errors',
         '--test-mode'],
        expectedCodeGenerated: false,
        expectedOutput: false,
        expectHint: true);
-
-    await test(
-       ['--output-type=dart'],
-       expectedCodeGenerated: false,
-       expectedOutput: false);
-    await test(
-       ['--output-type=dart', '--test-mode'],
-       expectedCodeGenerated: false,
-       expectedOutput: false);
-    await test(
-       ['--output-type=dart', '--generate-code-with-compile-time-errors'],
-       expectedCodeGenerated: false,
-       expectedOutput: false,
-       expectHint: true);
-    await test(
-       ['--output-type=dart',
-        '--generate-code-with-compile-time-errors',
-        '--test-mode'],
-       expectedCodeGenerated: false,
-       expectedOutput: false,
-       expectHint: true);
   });
 }