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

ios/chrome/browser/ui/favicon_view.mm

Index: ios/chrome/browser/ui/favicon_view.mm
diff --git a/ios/chrome/browser/ui/favicon_view.mm b/ios/chrome/browser/ui/favicon_view.mm
index 498792366b94781e1866dbd58ff2a5fbdbd69e24..a8de21f21cceb5e63e3d2f3135c43c0f58479c98 100644
--- a/ios/chrome/browser/ui/favicon_view.mm
+++ b/ios/chrome/browser/ui/favicon_view.mm
@@ -4,9 +4,12 @@
 
 #import "ios/chrome/browser/ui/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;
@@ -14,13 +17,12 @@ const CGFloat kDefaultCornerRadius = 3;
 
 @interface FaviconViewNew () {
   // Property releaser for FaviconViewNew.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_FaviconViewNew;
 }
 
 // Image view for the favicon.
-@property(nonatomic, retain) UIImageView* faviconImageView;
+@property(nonatomic, strong) UIImageView* faviconImageView;
 // Label for fallback favicon placeholder.
-@property(nonatomic, retain) UILabel* faviconFallbackLabel;
+@property(nonatomic, strong) UILabel* faviconFallbackLabel;
 
 @end
 
@@ -31,7 +33,6 @@ const CGFloat kDefaultCornerRadius = 3;
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
-    _propertyReleaser_FaviconViewNew.Init(self, [FaviconViewNew class]);
     _faviconImageView = [[UIImageView alloc] initWithFrame:self.bounds];
     _faviconImageView.clipsToBounds = YES;
     _faviconImageView.layer.cornerRadius = kDefaultCornerRadius;