Add CSDataSource in showcase

ios/showcase/content_suggestions/sc_content_suggestions_most_visited_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/showcase/content_suggestions/sc_content_suggestions_most_visited_item.h"
+
+#import "ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_most_visited_cell.h"
+#import "ios/chrome/browser/ui/favicon/favicon_view.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation SCContentSuggestionsMostVisitedItem
+
+@synthesize delegate;
+@synthesize attributes;
+@synthesize image;
+@synthesize suggestionIdentifier;
+@synthesize title;
+
+- (instancetype)initWithType:(NSInteger)type {
+  self = [super initWithType:type];
+  if (self) {
+    self.cellClass = [ContentSuggestionsMostVisitedCell class];
+  }
+  return self;
+}
+
+- (void)configureCell:(ContentSuggestionsMostVisitedCell*)cell {
+  [super configureCell:cell];
+  cell.titleLabel.text = self.title;
+  cell.accessibilityLabel = self.title;
+  [cell.faviconView configureWithAttributes:self.attributes];
+}
+
+@end