Adding close button in SigninPromoView

ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm

Index: ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm
diff --git a/ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm b/ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm
index 14bbbf0deb0817dd97185432e8df641d57a86198..e3163814b52bbe1e64fb5ff70928f7bdec88d0a6 100644
--- a/ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm
+++ b/ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.mm
@@ -13,11 +13,18 @@
 #error "This file requires ARC support."
 #endif
 
+namespace {
+// Close button size.
+const CGFloat kCloseButtonSize = 24;
+}
+
 @implementation BookmarkSigninPromoCell {
   SigninPromoView* _signinPromoView;
+  UIButton* _closeButton;
 }
 
 @synthesize signinPromoView = _signinPromoView;
+@synthesize closeButtonAction = _closeButtonAction;
 
 + (NSString*)reuseIdentifier {
   return @"BookmarkSigninPromoCell";
@@ -35,6 +42,21 @@
     _signinPromoView.translatesAutoresizingMaskIntoConstraints = NO;
     [contentView addSubview:_signinPromoView];
     AddSameConstraints(_signinPromoView, contentView);
+
+    _closeButton = [[UIButton alloc]
+        initWithFrame:CGRectMake(0, 0, kCloseButtonSize, kCloseButtonSize)];
+    [_closeButton addTarget:self
+                     action:@selector(closeButtonAction:)
+           forControlEvents:UIControlEventTouchUpInside];
+    _closeButton.translatesAutoresizingMaskIntoConstraints = NO;
+    [contentView addSubview:_closeButton];
+    [_closeButton setImage:[UIImage imageNamed:@"signin_promo_close_gray"]
+                  forState:UIControlStateNormal];
+    NSArray* buttonVisualConstraints =
+        @[ @"H:[closeButton]-|", @"V:|-[closeButton]" ];
+    NSDictionary* views = @{ @"closeButton" : _closeButton };
+    ApplyVisualConstraints(buttonVisualConstraints, views);
+
     _signinPromoView.backgroundColor = [UIColor whiteColor];
     _signinPromoView.textLabel.text =
         l10n_util::GetNSString(IDS_IOS_SIGNIN_PROMO_SETTINGS);
@@ -54,4 +76,14 @@
   [super layoutSubviews];
 }
 
+- (void)prepareForReuse {
+  _closeButtonAction = nil;
+}
+
+- (void)closeButtonAction:(id)sender {
+  if (_closeButtonAction) {
+    _closeButtonAction();

[msarda, 2017/05/04 11:48:08]

I think it would be better to set the closeButtonAction to nil after it is
called once. This would avoid it being called multiple times if the user taps
quickly more than once on the close button.

[jlebel, 2017/05/04 13:20:38]

I don't believe it is relevant. This should be done where the action is done.

+  }
+}
+
 @end