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

ios/chrome/browser/translate/translate_message_infobar_controller.mm

 // Copyright 2013 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.
 
 #include "ios/chrome/browser/translate/translate_message_infobar_controller.h"
 
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/translate/core/browser/translate_infobar_delegate.h"
 #include "ios/chrome/browser/translate/translate_infobar_tags.h"
 #import "ios/chrome/browser/ui/infobars/infobar_view.h"
 #import "ios/chrome/browser/ui/infobars/infobar_view_delegate.h"
 #include "ui/gfx/image/image.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface TranslateMessageInfoBarController ()
 
 // Action for any of the user defined buttons.
 - (void)infoBarButtonDidPress:(id)sender;
 
 @end
 
 @implementation TranslateMessageInfoBarController
 
 - (InfoBarView*)viewForDelegate:(infobars::InfoBarDelegate*)delegate
                           frame:(CGRect)frame {
-  base::scoped_nsobject<InfoBarView> infoBarView;
+  InfoBarView* infoBarView;
   translate::TranslateInfoBarDelegate* translateInfoBarDelegate =
       delegate->AsTranslateInfoBarDelegate();
-  infoBarView.reset(
-      [[InfoBarView alloc] initWithFrame:frame delegate:self.delegate]);
+  infoBarView =
+      [[InfoBarView alloc] initWithFrame:frame delegate:self.delegate];
   // Icon
   gfx::Image icon = translateInfoBarDelegate->GetIcon();
   if (!icon.IsEmpty())
     [infoBarView addLeftIcon:icon.ToUIImage()];
   // Text.
   [infoBarView addLabel:base::SysUTF16ToNSString(
                             translateInfoBarDelegate->GetMessageInfoBarText())];
   // Close button.
   [infoBarView addCloseButtonWithTag:TranslateInfoBarIOSTag::CLOSE
                               target:self
                               action:@selector(infoBarButtonDidPress:)];
   // Other button.
   base::string16 buttonText(
       translateInfoBarDelegate->GetMessageInfoBarButtonText());
   if (!buttonText.empty()) {
     [infoBarView addButton:base::SysUTF16ToNSString(buttonText)
                        tag:TranslateInfoBarIOSTag::MESSAGE
                     target:self
                     action:@selector(infoBarButtonDidPress:)];
   }
-  return [[infoBarView retain] autorelease];
+  return infoBarView;
 }
 
 #pragma mark - Handling of User Events
 
 - (void)infoBarButtonDidPress:(id)sender {
   // This press might have occurred after the user has already pressed a button,
   // in which case the view has been detached from the delegate and this press
   // should be ignored.
   if (!self.delegate) {
     return;
   }
   if ([sender isKindOfClass:[UIButton class]]) {
     NSUInteger buttonId = static_cast<UIButton*>(sender).tag;
     if (buttonId == TranslateInfoBarIOSTag::CLOSE) {
       self.delegate->InfoBarDidCancel();
     } else {
       DCHECK(buttonId == TranslateInfoBarIOSTag::MESSAGE);
       self.delegate->InfoBarButtonDidPress(buttonId);
     }
   }
 }
 
 @end