[ObjC ARC] Converts ios/chrome/browser/passwords:passwords to ARC.

ios/chrome/browser/passwords/ios_chrome_password_manager_driver.mm

 // Copyright 2015 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/chrome/browser/passwords/ios_chrome_password_manager_driver.h"
 
 #include "base/strings/string16.h"
 #include "components/autofill/core/common/password_form.h"
 #include "components/autofill/core/common/password_form_fill_data.h"
 #include "components/password_manager/core/browser/password_generation_manager.h"
 #include "components/password_manager/core/browser/password_manager.h"
 #import "ios/chrome/browser/passwords/password_generation_agent.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 using password_manager::PasswordAutofillManager;
 using password_manager::PasswordGenerationManager;
 using password_manager::PasswordManager;
 
 IOSChromePasswordManagerDriver::IOSChromePasswordManagerDriver(
     id<PasswordManagerDriverDelegate> delegate)
     : delegate_(delegate) {}
 
 IOSChromePasswordManagerDriver::~IOSChromePasswordManagerDriver() = default;
 
@@ skipping 61 matching lines @@
 
 autofill::AutofillDriver* IOSChromePasswordManagerDriver::GetAutofillDriver() {
   NOTIMPLEMENTED();
   return nullptr;
 }
 
 bool IOSChromePasswordManagerDriver::IsMainFrame() const {
   // On IOS only processing of password forms in main frame is implemented.
   return true;
 }