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

ios/chrome/browser/ui/history/favicon_view.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 "ios/chrome/browser/ui/history/favicon_view.h"
 
-#include "base/mac/objc_property_releaser.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Default corner radius for the favicon image view.
 const CGFloat kDefaultCornerRadius = 3;
 }
 
 @interface FaviconView () {
   // Property releaser for FaviconView.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_FaviconView;
 }
 // Size constraints for the favicon views.
 @property(nonatomic, copy) NSArray* faviconSizeConstraints;
 @end
 
 @implementation FaviconView
 
 @synthesize size = _size;
 @synthesize faviconImage = _faviconImage;
 @synthesize faviconFallbackLabel = _faviconFallbackLabel;
 @synthesize faviconSizeConstraints = _faviconSizeConstraints;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
-    _propertyReleaser_FaviconView.Init(self, [FaviconView class]);
     _faviconImage = [[UIImageView alloc] init];
     _faviconImage.clipsToBounds = YES;
     _faviconImage.layer.cornerRadius = kDefaultCornerRadius;
     _faviconImage.image = nil;
 
     _faviconFallbackLabel = [[UILabel alloc] initWithFrame:CGRectZero];
     _faviconFallbackLabel.backgroundColor = [UIColor clearColor];
     _faviconFallbackLabel.textAlignment = NSTextAlignmentCenter;
     _faviconFallbackLabel.isAccessibilityElement = NO;
     _faviconFallbackLabel.text = nil;
 
     [self addSubview:_faviconImage];
     [self addSubview:_faviconFallbackLabel];
 
     [_faviconImage setTranslatesAutoresizingMaskIntoConstraints:NO];
     [_faviconFallbackLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
     AddSameCenterConstraints(_faviconImage, self);
     AddSameSizeConstraint(_faviconImage, self);
     AddSameCenterConstraints(_faviconFallbackLabel, self);
     AddSameSizeConstraint(_faviconFallbackLabel, self);
-    _faviconSizeConstraints = [@[
+    _faviconSizeConstraints = @[
       [self.widthAnchor constraintEqualToConstant:0],
       [self.heightAnchor constraintEqualToConstant:0],
-    ] retain];
+    ];
     [NSLayoutConstraint activateConstraints:_faviconSizeConstraints];
   }
   return self;
 }
 
 - (void)setSize:(CGFloat)size {
   _size = size;
   for (NSLayoutConstraint* constraint in self.faviconSizeConstraints) {
     constraint.constant = size;
   }
 }
 
 @end