Add the new content widget including localised title.

ios/chrome/content_widget_extension/content_widget_view_controller.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.
+
+#import "ios/chrome/content_widget_extension/content_widget_view_controller.h"
+
+#import <NotificationCenter/NotificationCenter.h>
+
+#include "base/ios/ios_util.h"
+#include "base/mac/foundation_util.h"
+#include "base/strings/sys_string_conversions.h"
+#include "ios/chrome/common/app_group/app_group_constants.h"
+#include "ios/chrome/content_widget_extension/content_widget_view.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+// Using GURL in the extension is not wanted as it includes ICU which makes the
+// extension binary much larger; therefore, ios/chrome/common/x_callback_url.h
+// cannot be used. This class makes a very basic use of x-callback-url, so no
+// full implementation is required.
+NSString* const kXCallbackURLHost = @"x-callback-url";
+}  // namespace
+
+@interface ContentWidgetViewController ()
+@property(nonatomic, weak) ContentWidgetView* widgetView;
+
+// Updates the widget with latest data. Returns whether any visual updates
+// occured.
+- (BOOL)updateWidget;
+// Opens the main application with the given |URL|.
+- (void)openAppWithURL:(NSString*)URL;
+@end
+
+@implementation ContentWidgetViewController
+
+@synthesize widgetView = _widgetView;
+
+#pragma mark - UIViewController
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+
+  // A local variable is necessary here as the property is declared weak and the
+  // object would be deallocated before being retained by the addSubview call.
+  ContentWidgetView* widgetView = [[ContentWidgetView alloc] init];
+  self.widgetView = widgetView;
+  [self.view addSubview:self.widgetView];
+
+  if (base::ios::IsRunningOnIOS10OrLater()) {
+    self.extensionContext.widgetLargestAvailableDisplayMode =
+        NCWidgetDisplayModeExpanded;
+  }
+
+  self.widgetView.translatesAutoresizingMaskIntoConstraints = NO;
+  [NSLayoutConstraint activateConstraints:@[
+    [self.view.leadingAnchor
+        constraintEqualToAnchor:self.widgetView.leadingAnchor],
+    [self.view.trailingAnchor
+        constraintEqualToAnchor:self.widgetView.trailingAnchor],
+    [self.view.topAnchor constraintEqualToAnchor:self.widgetView.topAnchor],
+    [self.view.bottomAnchor
+        constraintEqualToAnchor:self.widgetView.bottomAnchor]
+  ]];
+}
+
+- (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
+  [self updateWidget];
+}
+
+- (void)widgetPerformUpdateWithCompletionHandler:
+    (void (^)(NCUpdateResult))completionHandler {
+  completionHandler([self updateWidget] ? NCUpdateResultNewData
+                                        : NCUpdateResultNoData);
+}
+
+- (BOOL)updateWidget {

[marq (ping after 24h), 2017/06/08 08:49:56]

This belongs in the 'internal' section, below.

[lody, 2017/06/08 09:19:57]

Done.

+  return NO;

[marq (ping after 24h), 2017/06/08 08:49:57]

Future CLs will actually perform an update?

[lody, 2017/06/08 09:19:57]

Yes

+}
+
+#pragma mark - NCWidgetProviding
+
+- (void)widgetActiveDisplayModeDidChange:(NCWidgetDisplayMode)activeDisplayMode
+                         withMaximumSize:(CGSize)maxSize {
+  BOOL isVariableHeight = (activeDisplayMode == NCWidgetDisplayModeExpanded);
+
+  // If the widget's height is not variable, the preferredContentSize is the
+  // maxSize. Widgets cannot be shrunk, and this ensures the view will lay
+  // itself out according to the actual screen size. (This is only likely to
+  // happen if the accessibility option for larger font is used.) If the widget
+  // is not a fixed size, if the fitting size for the widget's contents is
+  // larger than the maximum size for the current widget display mode, this
+  // maximum size is used for the widget. Otherwise, the preferredContentSize is
+  // set to the fitting size so that the widget gets the correct height.
+  if (isVariableHeight) {
+    CGSize fittingSize = [self.widgetView
+        systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
+    if (fittingSize.height < maxSize.height) {
+      self.preferredContentSize = fittingSize;
+      return;
+    }
+  }
+  self.preferredContentSize = maxSize;
+}
+
+// Implementing this method removes the leading edge inset for iOS version < 10.
+// TODO(crbug.com/720490): Remove implementation when dropping ios9 support.
+#if __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_10_0
+- (UIEdgeInsets)widgetMarginInsetsForProposedMarginInsets:
+    (UIEdgeInsets)defaultMa‌​rginInsets {
+  return UIEdgeInsetsZero;
+}
+#endif
+
+#pragma mark - internal
+
+- (void)openAppWithURL:(NSString*)URL {
+  NSUserDefaults* sharedDefaults =
+      [[NSUserDefaults alloc] initWithSuiteName:app_group::ApplicationGroup()];
+  NSString* defaultsKey =
+      base::SysUTF8ToNSString(app_group::kChromeAppGroupCommandPreference);
+
+  NSString* timePrefKey =
+      base::SysUTF8ToNSString(app_group::kChromeAppGroupCommandTimePreference);
+  NSString* appPrefKey =
+      base::SysUTF8ToNSString(app_group::kChromeAppGroupCommandAppPreference);
+  NSString* commandPrefKey = base::SysUTF8ToNSString(
+      app_group::kChromeAppGroupCommandCommandPreference);
+  NSString* paramPrefKey = base::SysUTF8ToNSString(
+      app_group::kChromeAppGroupCommandParameterPreference);
+
+  [sharedDefaults setObject:@{

[marq (ping after 24h), 2017/06/08 08:49:57]

Please extract the dictionary value out to a local variable to make this easier
to read.

[lody, 2017/06/08 09:19:57]

Done.

+    timePrefKey : [NSDate date],
+    appPrefKey : @"TodayExtension",
+    commandPrefKey :
+        base::SysUTF8ToNSString(app_group::kChromeAppGroupOpenURLCommand),
+    paramPrefKey : URL,
+  }
+                     forKey:defaultsKey];
+  [sharedDefaults synchronize];
+
+  NSString* scheme = base::mac::ObjCCast<NSString>([[NSBundle mainBundle]
+      objectForInfoDictionaryKey:@"KSChannelChromeScheme"]);
+  if (!scheme)
+    return;
+
+  NSURLComponents* urlComponents = [NSURLComponents new];
+  urlComponents.scheme = scheme;
+  urlComponents.host = kXCallbackURLHost;
+  urlComponents.path = [NSString

[marq (ping after 24h), 2017/06/08 08:49:56]

Optional nit: to just concatenate two strings, use -stringByAppendingString:

[@"/" stringByAppendingString:base::SysUTF8....]

[lody, 2017/06/08 09:19:57]

Done.

[lody, 2017/06/08 09:19:57]

Done.

+      stringWithFormat:@"/%@", base::SysUTF8ToNSString(
+                                   app_group::kChromeAppGroupXCallbackCommand)];
+
+  NSURL* openURL = [urlComponents URL];
+  [self.extensionContext openURL:openURL completionHandler:nil];
+}
+
+@end