I do a lot of HTML generation just with JavaScript and am finding myself creating `index.html` files that have code that looks like this:

     <!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>

It would be nice to be able to do:

     browserWindow.loadHTML('<!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>');

It would be even more awesome to do:

     browserWindow.loadScript(pathToScript);

I tried to use the `preload` option for `BrowserWindow` and using `loadURL('about:blank')`, but this has an unintended side effect of not allowing you to reference other script or CSS files using relative paths.

What do you think about proposed feature?
atom/browser/api/atom_api_web_contents.cc
args->ThrowError("Must specify either 'file' or 'files' option");
  }
}
void WebContents::CapturePage(mate::Arguments* args) {
  gfx::Rect rect;
  base::Callback<void(const gfx::Image&)> callback;
  if (!(args->Length() == 1 && args->GetNext(&callback)) &&
      !(args->Length() == 2 && args->GetNext(&rect)
                            && args->GetNext(&callback))) {
    args->ThrowError();
    return;
  }
  const auto view = web_contents()->GetRenderWidgetHostView();
  const auto host = view ? view->GetRenderWidgetHost() : nullptr;
  if (!view || !host) {
    callback.Run(gfx::Image());
    return;
  }
  
  const gfx::Size view_size = rect.IsEmpty() ? view->GetViewBounds().size() :
                                               rect.size();
  
  
  
  gfx::Size bitmap_size = view_size;
  const gfx::NativeView native_view = view->GetNativeView();
  const float scale =
      display::Screen::GetScreen()->GetDisplayNearestWindow(native_view)
      .device_scale_factor();
  if (scale > 1.0f)