Third try at landing gRPC refactoring. Previous issue failed on the waterfall

components/cronet/ios/test/start_cronet.mm

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Cronet/Cronet.h>
+#import <Foundation/Foundation.h>
+
+#include "components/cronet/ios/test/start_cronet.h"
+
+#include "base/strings/stringprintf.h"
+#include "base/strings/sys_string_conversions.h"
+#include "components/grpc_support/test/quic_test_server.h"
+
+namespace cronet {
+
+void StartCronetIfNecessary(int port) {
+  static bool initialized = false;
+  if (!initialized) {
+    initialized = true;
+    [Cronet setUserAgent:@"CronetTest/1.0.0.0" partial:NO];
+    [Cronet setHttp2Enabled:true];
+    [Cronet setQuicEnabled:true];
+    [Cronet setSslKeyLogFileName:@"SSLKEYLOGFILE"];
+    [Cronet addQuicHint:@"test.example.com" port:443 altPort:443];
+    [Cronet enableTestCertVerifierForTesting];
+    [Cronet start];
+  }
+  NSString* rules = base::SysUTF8ToNSString(
+      base::StringPrintf("MAP test.example.com 127.0.0.1:%d,"
+                         "MAP notfound.example.com ~NOTFOUND",
+                         port));
+  [Cronet setHostResolverRulesForTesting:rules];
+}
+
+}  // namespace cronet