Add a message to empty ContentSuggestions sections

ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_text_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/cells/content_suggestions_text_item.h"
+
+#import "ios/chrome/browser/ui/collection_view/cells/collection_view_text_cell.h"
+#import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
+#import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation ContentSuggestionsTextItem
+
+@synthesize text = _text;
+@synthesize detailText = _detailText;
+@synthesize suggestionIdentifier = _suggestionIdentifier;
+
+- (instancetype)initWithType:(NSInteger)type {
+  self = [super initWithType:type];
+  if (self) {
+    self.cellClass = [CollectionViewTextCell class];
+  }
+  return self;
+}
+
+- (void)configureCell:(CollectionViewTextCell*)cell {
+  [super configureCell:cell];
+
+  cell.textLabel.text = self.text;
+  cell.textLabel.textColor = [[MDCPalette greyPalette] tint900];
+  cell.textLabel.font = [MDCTypography body2Font];
+  cell.textLabel.numberOfLines = 0;
+  cell.detailTextLabel.text = self.detailText;
+  cell.detailTextLabel.textColor = [[MDCPalette greyPalette] tint500];
+  cell.detailTextLabel.font = [MDCTypography body1Font];
+  cell.detailTextLabel.numberOfLines = 0;
+
+  cell.isAccessibilityElement = YES;
+  if (self.detailText.length == 0) {
+    cell.accessibilityLabel = self.text;
+  } else {
+    cell.accessibilityLabel =
+        [NSString stringWithFormat:@"%@, %@", self.text, self.detailText];
+  }
+}
+
+@end