[iOS][Dark Mode] Fix separator color on suggested_content

Somehow, I had forgotten to set the color correctly for dark mode.

Bug: 1001062
Change-Id: I9d61043234b5b88439afdff43067cf6eedc23f71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1786444
Auto-Submit: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#693782}

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

@@ -28,6 +28,7 @@
 #import "ios/chrome/browser/ui/ui_feature_flags.h"
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
 #import "ios/chrome/common/colors/UIColor+cr_semantic_colors.h"
+#import "ios/chrome/common/colors/semantic_color_names.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -221,6 +222,7 @@ NSString* const kContentSuggestionsMostVisitedAccessibilityIdentifierPrefix =
   self.collectionView.backgroundColor = ntp_home::kNTPBackgroundColor();
   self.styler.cellStyle = MDCCollectionViewCellStyleCard;
   self.styler.cardBorderRadius = kCardBorderRadius;
+  self.styler.separatorColor = [UIColor colorNamed:kSeparatorColor];
   self.collectionView.translatesAutoresizingMaskIntoConstraints = NO;
 
   ApplyVisualConstraints(@[ @"V:|[collection]|", @"H:|[collection]|" ],