Default background for not suggested article images

ios/chrome/browser/ui/content_suggestions/content_suggestions_article_item.mm

 // Copyright 2017 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/content_suggestions/content_suggestions_article_item.h"
 
 #include "base/time/time.h"
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 #import "ios/chrome/browser/ui/util/i18n_string.h"
@@ skipping 38 matching lines @@
                     subtitle:(NSString*)subtitle
                     delegate:(id<ContentSuggestionsArticleItemDelegate>)delegate
                          url:(const GURL&)url {
   self = [super initWithType:type];
   if (self) {
     self.cellClass = [ContentSuggestionsArticleCell class];
     _title = [title copy];
     _subtitle = [subtitle copy];
     _articleURL = url;
     _delegate = delegate;
+    _image = [self emptyImageBackground];
   }
   return self;
 }
 
 - (void)configureCell:(ContentSuggestionsArticleCell*)cell {
   [super configureCell:cell];
-  if (!self.image && !self.imageFetched) {
+  if (!self.imageFetched) {
     self.imageFetched = YES;
-    // Fetch the image. During the fetch the cell's image should still be set to
-    // nil.
+    // Fetch the image. During the fetch the cell's image should still be set.
     [self.delegate loadImageForArticleItem:self];
   }
   cell.titleLabel.text = self.title;
   cell.subtitleLabel.text = self.subtitle;
   cell.imageView.image = self.image;
   [cell setPublisherName:self.publisher date:self.publishDate];
 }
 
+#pragma mark - Private
+
+- (UIImage*)emptyImageBackground {
+  // TODO(crbug.com/698171): Remove this function once we have real background
+  // image.
+  UIColor* color = [UIColor lightGrayColor];
+  CGRect rect = CGRectMake(0, 0, 1, 1);
+  UIGraphicsBeginImageContext(rect.size);
+  [color setFill];
+  UIRectFill(rect);
+  UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return image;
+}
+
 @end
 
 #pragma mark - ContentSuggestionsArticleCell
 
 @interface ContentSuggestionsArticleCell ()
 
 @property(nonatomic, strong) UILabel* publisherLabel;
 
 // Applies the constraints on the elements. Called in the init.
 - (void)applyConstraints;
@@ skipping 62 matching lines @@
 // Implements -layoutSubviews as per instructions in documentation for
 // +[MDCCollectionViewCell cr_preferredHeightForWidth:forItem:].
 - (void)layoutSubviews {
   [super layoutSubviews];
 
   // Adjust the text label preferredMaxLayoutWidth when the parent's width
   // changes, for instance on screen rotation.
   CGFloat parentWidth = CGRectGetWidth(self.contentView.bounds);
 
   self.titleLabel.preferredMaxLayoutWidth =
-      parentWidth - self.imageView.bounds.size.width - 3 * kStandardSpacing;
+      parentWidth - kImageSize - 3 * kStandardSpacing;
   self.subtitleLabel.preferredMaxLayoutWidth =
-      parentWidth - self.imageView.bounds.size.width - 3 * kStandardSpacing;
+      parentWidth - kImageSize - 3 * kStandardSpacing;
 
   // Re-layout with the new preferred width to allow the label to adjust its
   // height.
   [super layoutSubviews];
 }
 
 #pragma mark - Private
 
 - (void)applyConstraints {
   [NSLayoutConstraint activateConstraints:@[
@@ skipping 19 matching lines @@
       @{
         @"image" : _imageView,
         @"title" : _titleLabel,
         @"text" : _subtitleLabel,
         @"publish" : _publisherLabel,
       },
       @{ @"space" : @(kStandardSpacing) });
 }
 
 @end