Convert //ios/web_view/internal to ARC.

ios/web_view/internal/criwv_web_client.mm

 // Copyright 2014 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 "ios/web_view/internal/criwv_web_client.h"
 
 #include "base/strings/sys_string_conversions.h"
 #include "ios/web/public/user_agent.h"
 #include "ios/web_view/internal/criwv_browser_state.h"
 #import "ios/web_view/internal/criwv_web_main_parts.h"
 #import "ios/web_view/public/criwv_delegate.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace ios_web_view {
 
 CRIWVWebClient::CRIWVWebClient(id<CRIWVDelegate> delegate)
     : delegate_(delegate), web_main_parts_(nullptr) {}
 
 CRIWVWebClient::~CRIWVWebClient() {}
 
 web::WebMainParts* CRIWVWebClient::CreateWebMainParts() {
   web_main_parts_ = new CRIWVWebMainParts(delegate_);
   return web_main_parts_;
@@ skipping 10 matching lines @@
 std::string CRIWVWebClient::GetProduct() const {
   return base::SysNSStringToUTF8([delegate_ partialUserAgent]);
 }
 
 std::string CRIWVWebClient::GetUserAgent(bool desktop_user_agent) const {
   std::string product = GetProduct();
   return web::BuildUserAgentFromProduct(product);
 }
 
 }  // namespace ios_web_view