Upstream Chrome on iOS source code [9/11].

ios/chrome/browser/ui/tabs/tab_strip_view.mm

+// Copyright 2012 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/tabs/tab_strip_view.h"
+
+@implementation TabStripView
+
+@synthesize layoutDelegate = layoutDelegate_;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  if ((self = [super initWithFrame:frame])) {
+    self.showsHorizontalScrollIndicator = NO;
+    self.showsVerticalScrollIndicator = NO;
+  }
+  return self;
+}
+
+- (BOOL)touchesShouldCancelInContentView:(UIView*)view {
+  // The default implementation returns YES for all views except for UIControls.
+  // Override to return YES for UIControls as well.
+  return YES;
+}
+
+- (void)layoutSubviews {
+  [layoutDelegate_ layoutTabStripSubviews];
+}
+
+- (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection {
+  [super traitCollectionDidChange:previousTraitCollection];
+  [layoutDelegate_ traitCollectionDidChange:previousTraitCollection];
+}
+
+@end