* Electron version: 1.6.10
* Operating system: macOS Sierra 10.12.4 (16E195)

# Improve Handoff API support

Hi!

Today the API of Handoff provides the methods: `setUserActivity`, `getCurrentActivityType` and dispatch the event `continue-activity`

I'm using Handoff and noticed that in some circumstances the broadcast takes a long time to update its userInfo which does not happen on the native iOS client

1. To invalidate or resign the current activity we currently need to create a non-existing activity type and set it as the current activity. There's no way to handle the activity life cycle through electron.
2. When we need to update a given user activity userInfo frequently (i.e in response to a search bar's text changes), we have no efficient way. Setting a new userActivity with the updated information takes several seconds to bridge, whereas doing this on iOS native app is instantaneous.

I believe that exposing a bit more of the NSUserActivity API to Electron would help, namely `becomeCurrent`, `resignCurrent` and `invalidate` which would address point 1, and `needsSave` and a new event to allow updating an activity when needed to address point 2.
These are described in more detail in https://developer.apple.com/reference/foundation/nsuseractivity.

I'm are open to help in any way i can such as explaining how the native API work, providing sample code or testing possible implementations

Thank you!
atom/browser/api/atom_api_app.cc
const std::string& info_type) {
  auto* const gpu_data_manager = content::GpuDataManagerImpl::GetInstance();
  util::Promise promise(isolate);
  v8::Local<v8::Promise> handle = promise.GetHandle();
  if (info_type != "basic" && info_type != "complete") {
    promise.RejectWithErrorMessage(
        "Invalid info type. Use 'basic' or 'complete'");
    return handle;
  }
  std::string reason;
  if (!gpu_data_manager->GpuAccessAllowed(&reason)) {
    promise.RejectWithErrorMessage("GPU access not allowed. Reason: " + reason);
    return handle;
  }
  auto* const info_mgr = GPUInfoManager::GetInstance();
  if (info_type == "complete") {
#if defined(OS_WIN) || defined(OS_MACOSX)
    info_mgr->FetchCompleteInfo(std::move(promise));
#else
    info_mgr->FetchBasicInfo(std::move(promise));
#endif
  } else  {
    info_mgr->FetchBasicInfo(std::move(promise));
  }
  return handle;
}
static void RemoveNoSandboxSwitch(base::CommandLine* command_line) {