[ObjC ARC] Converts ios/chrome/browser/ui/omnibox:omnibox_internal to ARC.

ios/chrome/browser/ui/omnibox/truncating_attributed_label.h

 // Copyright (c) 2012 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_OMNIBOX_TRUNCATING_ATTRIBUTED_LABEL_H_
 #define IOS_CHROME_BROWSER_UI_OMNIBOX_TRUNCATING_ATTRIBUTED_LABEL_H_
 
 #import <CoreText/CoreText.h>
 #import <QuartzCore/QuartzCore.h>
 #import <UIKit/UIKit.h>
@@ skipping 14 matching lines @@
 // highlighted, minimumFontSize, and numberOfLines.
 @interface OmniboxPopupTruncatingLabel : UIView
 
 // Which side(s) to truncate.
 @property(nonatomic, assign) OmniboxPopupTruncatingMode truncateMode;
 
 // Text alignment.
 @property(nonatomic, assign) NSTextAlignment textAlignment;
 
 // For display of an attributed string.
-@property(nonatomic, retain) NSMutableAttributedString* attributedText;
+@property(nonatomic, strong) NSMutableAttributedString* attributedText;
 
 // Set the label highlight state.
 @property(nonatomic, assign) BOOL highlighted;
 
 // Set the label highlight color.
-@property(nonatomic, retain) NSMutableAttributedString* highlightedText;
+@property(nonatomic, strong) NSMutableAttributedString* highlightedText;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_OMNIBOX_TRUNCATING_ATTRIBUTED_LABEL_H_