From https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/Handoff/AdoptingHandoff/AdoptingHandoff.html#//apple_ref/doc/uid/TP40014338-CH2-SW19:

> When using a native app on the originating device, the user may want to continue the activity on another device that does not have a corresponding native app. If there is a web page that corresponds to the activity, it can still be handed off. For example, video library apps enable users to browse movies available for viewing, and mail apps enable users to read and compose email, and in many cases users can do the same activity though a web-page interface. In this case, the native app knows the URL for the web interface, possibly including syntax designating a particular video being browsed or message being read. **So, when the native app creates the NSUserActivity object, it sets the webpageURL property, and if the receiving device doesn't have an app that supports the user activity’s activityType, it can resume the activity in the default web-browser of the continuing platform.** :heart:

You can read more about the property at: https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSUserActivity_Class/index.html#//apple_ref/occ/cl/NSUserActivity/

atom/browser/browser.h
std::string GetName() const;
  
  void SetName(const std::string& name);
  
  void AddRecentDocument(const base::FilePath& path);
  
  void ClearRecentDocuments();
  
  void SetAppUserModelID(const base::string16& name);
  
  bool RemoveAsDefaultProtocolClient(const std::string& protocol);
  
  bool SetAsDefaultProtocolClient(const std::string& protocol);
  
  bool IsDefaultProtocolClient(const std::string& protocol);
#if defined(OS_MACOSX)
  
  void Hide();
  
  void Show();
  
  void SetUserActivity(const std::string& type,
                       const base::DictionaryValue& user_info);
  
  std::string GetCurrentActivityType();
  
  bool ContinueUserActivity(const std::string& type,
                            const base::DictionaryValue& user_info);
  
  enum BounceType {