- Electron version: 0.37.6
- Operating system: Windows 10

In VSCode, in order to support screen readers while editing text, we set the contents of a `<textarea>` to the contents of the line and lines surrounding the cursor and we mirror the editor selection in the `<textarea>` via `setSelectionRange`.

Chromium is not the fastest when it comes to setting large amounts of text :) (such as > 10,000 characters) and basically stalls all the time. Apparently, Electron already has some knowledge about when a screen reader is attached to the main process window (in C++ code). Is it possible to expose this as a getter + event when it first happens in the `electron` API.

We could then maintain this costly `<textarea>` sync only when really needed.

atom/browser/native_window_views_win.cc
if (HIWORD(w_param) == THBN_CLICKED)
        return taskbar_host_.HandleThumbarButtonEvent(LOWORD(w_param));
      return false;
    case WM_SIZE:
      
      HandleSizeEvent(w_param, l_param);
      return false;
    case WM_MOVING: {
      if (!movable_)
        ::GetWindowRect(GetAcceleratedWidget(), (LPRECT)l_param);
      return false;
    }
    default:
      return false;
  }
}
void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
  
  
  switch (w_param) {
    case SIZE_MAXIMIZED:
      last_window_state_ = ui::SHOW_STATE_MAXIMIZED;
      NotifyWindowMaximize();
      break;
    case SIZE_MINIMIZED:
      last_window_state_ = ui::SHOW_STATE_MINIMIZED;
      NotifyWindowMinimize();
      break;
    case SIZE_RESTORED:
      if (last_window_state_ == ui::SHOW_STATE_NORMAL) {