Upstream Chrome on iOS source code [3/11].

ios/chrome/browser/ui/bookmarks/bars/bookmark_top_bar.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/bookmarks/bars/bookmark_top_bar.h"
+
+#include "base/mac/objc_property_releaser.h"
+#include "base/mac/scoped_nsobject.h"
+
+@interface BookmarkTopBar () {
+  base::mac::ObjCPropertyReleaser _propertyReleaser_BookmarkBar;
+}
+@property(nonatomic, retain) UIView* contentView;
+@end
+
+@implementation BookmarkTopBar
+
+@synthesize contentView = _contentView;
+
++ (CGFloat)expectedContentViewHeight {
+  return 56.0;
+}
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) {
+    _propertyReleaser_BookmarkBar.Init(self, [BookmarkTopBar class]);
+
+    self.autoresizingMask = UIViewAutoresizingFlexibleBottomMargin |
+                            UIViewAutoresizingFlexibleWidth;
+
+    base::scoped_nsobject<UIView> contentView([[UIView alloc] init]);
+    self.contentView.backgroundColor = [UIColor clearColor];
+    [self addSubview:contentView];
+    self.contentView = contentView;
+
+    [self statelessLayoutContentView];
+  }
+  return self;
+}
+
+- (void)layoutSubviews {
+  [super layoutSubviews];
+
+  // The content view.
+  [self statelessLayoutContentView];
+}
+
+- (void)statelessLayoutContentView {
+  self.contentView.frame = CGRectMake(
+      0,
+      CGRectGetHeight(self.bounds) - [[self class] expectedContentViewHeight],
+      CGRectGetWidth(self.bounds), [[self class] expectedContentViewHeight]);
+}
+
+@end