Format samples and samples-dev directories.

samples/sample_extension/test/sample_extension_test_helper.dart

 // Copyright (c) 2013, 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.
 //
 // Dart test program for testing native extensions.
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
@@ skipping 36 matching lines @@
 Future testNativeExtensions(String snapshotKind) async {
   String buildDirectory = dirname(Platform.executable);
   Directory tempDirectory =
       Directory.systemTemp.createTempSync('sample_extension_');
   try {
     String testDirectory = tempDirectory.path;
     String sourceDirectory = Platform.script.resolve('..').toFilePath();
 
     // Copy sample_extension dart files and sample_extension tests to the
     // temporary test directory.
-    for (var file in ['sample_synchronous_extension.dart',
-                      'sample_asynchronous_extension.dart',
-                      'test_sample_synchronous_extension.dart',
-                      'test_sample_asynchronous_extension.dart']) {
+    for (var file in [
+      'sample_synchronous_extension.dart',
+      'sample_asynchronous_extension.dart',
+      'test_sample_synchronous_extension.dart',
+      'test_sample_asynchronous_extension.dart'
+    ]) {
       await copyFileToDirectory(join(sourceDirectory, file), testDirectory);
     }
 
-    for (var test in ['test_sample_synchronous_extension.dart',
-                      'test_sample_asynchronous_extension.dart']) {
+    for (var test in [
+      'test_sample_synchronous_extension.dart',
+      'test_sample_asynchronous_extension.dart'
+    ]) {
       String script = join(testDirectory, test);
       String snapshot;
       if (snapshotKind == null) {
         snapshot = script;
       } else {
         snapshot = join(testDirectory, "$test.snapshot");
         await run(Platform.executable,
-                  ['--snapshot=$snapshot',
-                   '--snapshot-kind=$snapshotKind',
-                   script]);
+            ['--snapshot=$snapshot', '--snapshot-kind=$snapshotKind', script]);
       }
 
       await run(Platform.executable, [snapshot]);
     }
   } finally {
     await tempDirectory.deleteSync(recursive: true);
   }
 }