- 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/api/atom_api_app.cc
Browser::UserTask* out) {
    mate::Dictionary dict;
    if (!ConvertFromV8(isolate, val, &dict))
      return false;
    if (!dict.Get("program", &(out->program)) ||
        !dict.Get("title", &(out->title)))
      return false;
    if (dict.Get("iconPath", &(out->icon_path)) &&
        !dict.Get("iconIndex", &(out->icon_index)))
      return false;
    dict.Get("arguments", &(out->arguments));
    dict.Get("description", &(out->description));
    return true;
  }
};
#endif
#if defined(OS_MACOSX)
template<>
struct Converter<Browser::LoginItemSettings> {
  static bool FromV8(v8::Isolate* isolate, v8::Local<v8::Value> val,