Default state for the favicon view

ios/chrome/browser/ui/favicon/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/favicon/favicon_view.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;
+// Percentage of white for the default background, when there is no attributes.
+const CGFloat kDefaultWhitePercentage = 0.47;
 }
 
 @interface FaviconViewNew () {
   // Property releaser for FaviconViewNew.
 }
 
 // Image view for the favicon.
 @property(nonatomic, strong) UIImageView* faviconImageView;
 // Label for fallback favicon placeholder.
 @property(nonatomic, strong) UILabel* faviconFallbackLabel;
 
 @end
 
 @implementation FaviconViewNew
 @synthesize faviconImageView = _faviconImageView;
 @synthesize faviconFallbackLabel = _faviconFallbackLabel;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     _faviconImageView = [[UIImageView alloc] initWithFrame:self.bounds];
     _faviconImageView.clipsToBounds = YES;
     _faviconImageView.layer.cornerRadius = kDefaultCornerRadius;
     _faviconImageView.image = nil;
 
     _faviconFallbackLabel = [[UILabel alloc] initWithFrame:self.bounds];
-    _faviconFallbackLabel.backgroundColor = [UIColor clearColor];
+    _faviconFallbackLabel.backgroundColor =
+        [UIColor colorWithWhite:kDefaultWhitePercentage alpha:1];
     _faviconFallbackLabel.textAlignment = NSTextAlignmentCenter;
     _faviconFallbackLabel.isAccessibilityElement = NO;
     _faviconFallbackLabel.clipsToBounds = YES;
     _faviconFallbackLabel.layer.cornerRadius = kDefaultCornerRadius;
     _faviconFallbackLabel.text = nil;
 
     [self addSubview:_faviconFallbackLabel];
     [self addSubview:_faviconImageView];
 
     [_faviconImageView setTranslatesAutoresizingMaskIntoConstraints:NO];
     [_faviconFallbackLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
 
     // Both image and fallback label are centered and match the size of favicon.
     AddSameCenterConstraints(_faviconImageView, self);
     AddSameCenterConstraints(_faviconFallbackLabel, self);
     AddSameSizeConstraint(_faviconFallbackLabel, self);
     AddSameSizeConstraint(_faviconImageView, self);
   }
   return self;
 }
 
 - (void)configureWithAttributes:(FaviconAttributes*)attributes {
+  if (!attributes) {
+    self.faviconFallbackLabel.backgroundColor =
+        [UIColor colorWithWhite:kDefaultWhitePercentage alpha:1];
+    self.faviconFallbackLabel.text = nil;
+    self.faviconFallbackLabel.hidden = NO;
+    self.faviconImageView.hidden = YES;
+    return;
+  }
+
   if (attributes.faviconImage) {
     self.faviconImageView.image = attributes.faviconImage;
     self.faviconImageView.hidden = NO;
     self.faviconFallbackLabel.hidden = YES;
   } else {
     self.faviconFallbackLabel.backgroundColor = attributes.backgroundColor;
     self.faviconFallbackLabel.textColor = attributes.textColor;
     self.faviconFallbackLabel.text = attributes.monogramString;
     self.faviconFallbackLabel.hidden = NO;
     self.faviconImageView.hidden = YES;
   }
 }
 
 - (void)setFont:(UIFont*)font {
   self.faviconFallbackLabel.font = font;
 }
 
 #pragma mark - UIView
 
 - (CGSize)intrinsicContentSize {
   return CGSizeMake(kFaviconPreferredSize, kFaviconPreferredSize);
 }
 
 @end