[CRD iOS] Add the host setup instruction page

remoting/ios/app/host_setup_header_view.mm

+// Copyright 2017 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.
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+#import "remoting/ios/app/host_setup_header_view.h"
+
+#import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
+#import "remoting/ios/app/remoting_theme.h"
+
+static const CGFloat kSetupTitleInset = 22.f;
+static const CGFloat kBottomPadding = 6.f;
+
+// TODO(yuweih): i18n
+static NSString* const kSetupTitle =
+    @"Welcome to Chrome Remote Desktop.\n"
+    @"Let's get you setup.";
+
+@implementation HostSetupHeaderView
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  if (self = [super initWithFrame:frame]) {
+    [self commonInit];
+  }
+  return self;
+}
+
+- (void)commonInit {
+  self.backgroundColor = RemotingTheme.setupListBackgroundColor;
+
+  UILabel* titleLabel = [[UILabel alloc] init];
+  titleLabel.text = kSetupTitle;
+  titleLabel.font = MDCTypography.titleFont;
+  titleLabel.numberOfLines = 2;
+  titleLabel.adjustsFontSizeToFitWidth = YES;
+  titleLabel.textColor = RemotingTheme.setupListTextColor;
+  [self addSubview:titleLabel];
+  titleLabel.translatesAutoresizingMaskIntoConstraints = NO;
+  [NSLayoutConstraint activateConstraints:@[
+    [titleLabel.leadingAnchor constraintEqualToAnchor:self.leadingAnchor
+                                             constant:kSetupTitleInset],
+    [titleLabel.trailingAnchor constraintEqualToAnchor:self.trailingAnchor
+                                              constant:-kSetupTitleInset],
+    [titleLabel.bottomAnchor constraintEqualToAnchor:self.bottomAnchor
+                                            constant:-kBottomPadding],
+  ]];
+}
+
+@end