Finish integrating HelloServices model on iOS (#4820)

This patch changes the default `flutter create` command to generate a
HelloServices-style app on iOS. As a consequence, the Atom integration now
fully works with HelloServices.

packages/flutter_tools/lib/src/ios/mac.dart

diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index 163b05f..962ced7 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -105,16 +105,7 @@
   bool codesign: true
 }) async {
   String flutterProjectPath = Directory.current.path;
-
-  if (xcodeProjectRequiresUpdate(mode, target)) {
-    printTrace('Initializing the Xcode project.');
-    if ((await setupXcodeProjectHarness(flutterProjectPath, mode, target)) != 0) {
-      printError('Could not initialize the Xcode project.');
-      return new XcodeBuildResult(false);
-    }
-  } else {
-    updateXcodeGeneratedProperties(flutterProjectPath, mode, target);
-  }
+  updateXcodeGeneratedProperties(flutterProjectPath, mode, target);
 
   if (!_checkXcodeVersion())
     return new XcodeBuildResult(false);
@@ -130,7 +121,6 @@
     'xcodebuild',
     'clean',
     'build',
-    '-target', 'Runner',
     '-configuration', 'Release',
     'ONLY_ACTIVE_ARCH=YES',
   ];

packages/flutter_tools/lib/src/ios/setup_xcodeproj.dart

diff --git a/packages/flutter_tools/lib/src/ios/setup_xcodeproj.dart b/packages/flutter_tools/lib/src/ios/setup_xcodeproj.dart
index 6cf48bf..210dbf8 100644
--- a/packages/flutter_tools/lib/src/ios/setup_xcodeproj.dart
+++ b/packages/flutter_tools/lib/src/ios/setup_xcodeproj.dart
@@ -2,16 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 
-import '../base/file_system.dart' show copyFolderSync;
 import '../build_info.dart';
 import '../cache.dart';
 import '../globals.dart';
-import '../version.dart';
 
 void updateXcodeGeneratedProperties(String projectPath, BuildMode mode, String target) {
   StringBuffer localsBuffer = new StringBuffer();
@@ -37,54 +34,7 @@
   if (tools.isLocalEngine)
     localsBuffer.writeln('LOCAL_ENGINE=${tools.engineBuildPath}');
 
-  File localsFile = new File(path.join(projectPath, 'ios', '.generated', 'Flutter', 'Generated.xcconfig'));
+  File localsFile = new File(path.join(projectPath, 'ios', 'Flutter', 'Generated.xcconfig'));
   localsFile.createSync(recursive: true);
   localsFile.writeAsStringSync(localsBuffer.toString());
 }
-
-bool xcodeProjectRequiresUpdate(BuildMode mode, String target) {
-  File revisionFile = new File(path.join(Directory.current.path, 'ios', '.generated', 'REVISION'));
-
-  // If the revision stamp does not exist, the Xcode project definitely requires
-  // an update
-  if (!revisionFile.existsSync()) {
-    printTrace("A revision stamp does not exist. The Xcode project has never been initialized.");
-    return true;
-  }
-
-  if (revisionFile.readAsStringSync() != _getCurrentXcodeRevisionString(mode, target)) {
-    printTrace("The revision stamp and the Flutter engine revision differ or the build mode has changed.");
-    printTrace("Project needs to be updated.");
-    return true;
-  }
-
-  printTrace("Xcode project is up to date.");
-  return false;
-}
-
-Future<int> setupXcodeProjectHarness(String flutterProjectPath, BuildMode mode, String target) async {
-  // Step 1: Copy templates into user project directory
-  String iosFilesPath = path.join(flutterProjectPath, 'ios');
-  String xcodeProjectPath = path.join(iosFilesPath, '.generated');
-  String templatesPath = path.join(Cache.flutterRoot, 'packages', 'flutter_tools', 'templates', 'build-ios');
-  copyFolderSync(templatesPath, xcodeProjectPath);
-
-  // Step 2: Populate the Generated.xcconfig with project specific paths
-  updateXcodeGeneratedProperties(flutterProjectPath, mode, target);
-
-  // Step 3: Write the REVISION file
-  File revisionFile = new File(path.join(xcodeProjectPath, 'REVISION'));
-  revisionFile.createSync();
-  revisionFile.writeAsStringSync(_getCurrentXcodeRevisionString(mode, target));
-
-  // Step 4: Tell the user the location of the generated project.
-  printStatus('Xcode project created in $iosFilesPath/.');
-
-  return 0;
-}
-
-String _getCurrentXcodeRevisionString(BuildMode mode, String target) => (new StringBuffer()
-    ..write('${FlutterVersion.getVersion().frameworkRevision}')
-    ..write('-${tools.isLocalEngine ? tools.engineBuildPath : getModeName(mode)}')
-    ..write('::$target')
-    ).toString();