Upstream Chrome on iOS source code [5/11].

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"
+
+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 = [@[
+      [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