[iOS] Add dark mode row highlight colors to the omnibox popup

The code in OmniboxPopupRow wasn't actually doing anything. The default
UIKit method of row highlighting is to insert a view in the table
cell's subviews at index 0, so the cell's background color is always
covered. Setting selectedBackgroundView is the modern way of
controlling this color.

Bug: 976662
Change-Id: If0d18fc3edc82f6cb2eda0324dabe23e9ba9a085
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1735164
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684276}

ios/chrome/browser/ui/omnibox/popup/omnibox_popup_row.mm

@@ -55,6 +55,10 @@ const CGFloat kLeadingPaddingIpadCompact = 71;
   if (self) {
     self.isAccessibilityElement = YES;
     self.backgroundColor = UIColor.clearColor;
+    self.selectedBackgroundView = [[UIView alloc] initWithFrame:CGRectZero];
+    self.selectedBackgroundView.backgroundColor = color::IncognitoDynamicColor(
+        _incognito, [UIColor colorNamed:kTableViewRowHighlightColor],
+        [UIColor colorNamed:kTableViewRowHighlightDarkColor]);
 
     _incognito = incognito;
 
@@ -143,27 +147,6 @@ const CGFloat kLeadingPaddingIpadCompact = 71;
   _imageView.frame = frame;
 }
 
-- (void)updateHighlightBackground:(BOOL)highlighted {
-  // Set the background color to match the color of selected table view cells
-  // when their selection style is UITableViewCellSelectionStyleGray.
-  if (highlighted) {
-    self.backgroundColor = _incognito ? [UIColor colorWithWhite:1 alpha:0.1]
-                                      : [UIColor colorWithWhite:0 alpha:0.05];
-  } else {
-    self.backgroundColor = [UIColor clearColor];
-  }
-}
-
-- (void)setHighlighted:(BOOL)highlighted animated:(BOOL)animated {
-  [super setHighlighted:highlighted animated:animated];
-  [self updateHighlightBackground:highlighted];
-}
-
-- (void)setHighlighted:(BOOL)highlighted {
-  [super setHighlighted:highlighted];
-  [self updateHighlightBackground:highlighted];
-}
-
 - (void)setTabMatch:(BOOL)tabMatch {
   _tabMatch = tabMatch;
   [self updateTrailingButtonImages];

ios/chrome/browser/ui/omnibox/popup/omnibox_popup_row_cell.mm

@@ -66,6 +66,11 @@ NSString* const kOmniboxPopupRowSwitchTabAccessibilityIdentifier =
               reuseIdentifier:(NSString*)reuseIdentifier {
   self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
   if (self) {
+    self.selectedBackgroundView = [[UIView alloc] initWithFrame:CGRectZero];
+    self.selectedBackgroundView.backgroundColor = color::IncognitoDynamicColor(
+        _incognito, [UIColor colorNamed:kTableViewRowHighlightColor],
+        [UIColor colorNamed:kTableViewRowHighlightDarkColor]);
+
     _textTruncatingLabel =
         [[OmniboxPopupTruncatingLabel alloc] initWithFrame:CGRectZero];
     _textTruncatingLabel.translatesAutoresizingMaskIntoConstraints = NO;