allow --dart-sdk with --persisent_worker

pkg/analyzer_cli/lib/src/build_mode.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.
 
 library analyzer_cli.src.build_mode;
 
 import 'dart:core' hide Resource;
 import 'dart:io' as io;
 
 import 'package:protobuf/protobuf.dart';
@@ skipping 296 matching lines @@
  */
 class WorkerLoop {
   static const int EXIT_CODE_OK = 0;
   static const int EXIT_CODE_ERROR = 15;
 
   final WorkerConnection connection;
 
   final StringBuffer errorBuffer = new StringBuffer();
   final StringBuffer outBuffer = new StringBuffer();
 
-  WorkerLoop(this.connection);
+  final String dartSdkPath;
 
-  factory WorkerLoop.std({io.Stdin stdinStream, io.Stdout stdoutStream}) {
+  WorkerLoop(this.connection, {this.dartSdkPath});
+
+  factory WorkerLoop.std(
+      {io.Stdin stdinStream, io.Stdout stdoutStream, String dartSdkPath}) {
     stdinStream ??= io.stdin;
     stdoutStream ??= io.stdout;
     WorkerConnection connection =
         new StdWorkerConnection(stdinStream, stdoutStream);
-    return new WorkerLoop(connection);
+    return new WorkerLoop(connection, dartSdkPath: dartSdkPath);
   }
 
   /**
    * Performs analysis with given [options].
    */
   void analyze(CommandLineOptions options) {
+    options.dartSdkPath ??= dartSdkPath;
     new BuildMode(options, new AnalysisStats()).analyze();
   }
 
   /**
    * Perform a single loop step.  Return `true` if should exit the loop.
    */
   bool performSingle() {
     try {
       WorkRequest request = connection.readRequest();
       if (request == null) {
@@ skipping 73 matching lines @@
   void writeResponse(WorkResponse response) {
     var responseBuffer = response.writeToBuffer();
 
     var writer = new CodedBufferWriter();
     writer.writeInt32NoTag(responseBuffer.length);
     writer.writeRawBytes(responseBuffer);
 
     _stdoutStream.add(writer.toBuffer());
   }
 }