Upstream Chrome on iOS source code [6/11].

ios/chrome/browser/ui/ntp/recent_tabs/views/spacers_view.mm

+// Copyright 2014 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/ntp/recent_tabs/views/spacers_view.h"
+
+#include "base/logging.h"
+#import "ios/chrome/browser/ui/ntp/recent_tabs/views/views_utils.h"
+#include "ios/chrome/browser/ui/ui_util.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+
+// Desired height of the view.
+const CGFloat kHeaderDesiredHeightIPhone = 8;
+const CGFloat kHeaderDesiredHeightIPad = 48;
+const CGFloat kFooterDesiredHeight = 17;
+
+// Text color.
+const int kSeparatorColor = 0x5a5a5a;
+const CGFloat kSeparatorAlpha = 0.1;
+
+}  // namespace
+
+@implementation RecentlyTabsTopSpacingHeader
+
++ (CGFloat)desiredHeightInUITableViewCell {
+  if (IsIPadIdiom()) {
+    return kHeaderDesiredHeightIPad;
+  } else {
+    return kHeaderDesiredHeightIPhone;
+  }
+}
+
+@end
+
+@implementation RecentlyClosedSectionFooter
+
+- (instancetype)initWithFrame:(CGRect)aRect {
+  self = [super initWithFrame:CGRectZero];
+  if (self) {
+    // Create and add separator.
+    UIView* separator = [[UIView alloc] init];
+    [separator setTranslatesAutoresizingMaskIntoConstraints:NO];
+    UIColor* separatorColor = UIColorFromRGB(kSeparatorColor, kSeparatorAlpha);
+    [separator setBackgroundColor:separatorColor];
+    [self addSubview:separator];
+
+    // Set constraints on separator.
+    NSDictionary* viewsDictionary = @{ @"separator" : separator };
+    // This set of constraints should match the constraints set on the
+    // RecentTabsTableViewController.
+    // clang-format off
+    NSArray* constraints = @[
+      @"V:|-(8)-[separator(==1)]",
+      @"H:|-(16)-[separator(<=516)]-(16)-|",
+      @"H:[separator(==516@500)]"
+    ];
+    // clang-format on
+    [self addConstraint:[NSLayoutConstraint
+                            constraintWithItem:separator
+                                     attribute:NSLayoutAttributeCenterX
+                                     relatedBy:NSLayoutRelationEqual
+                                        toItem:self
+                                     attribute:NSLayoutAttributeCenterX
+                                    multiplier:1
+                                      constant:0]];
+    ApplyVisualConstraints(constraints, viewsDictionary, self);
+  }
+  return self;
+}
+
++ (CGFloat)desiredHeightInUITableViewCell {
+  return kFooterDesiredHeight;
+}
+
+@end