* Output of `node_modules/.bin/electron --version`: 2.0.0
* Operating System (Platform and Version): Windows 10

**Expected Behavior**
When I disable a window twice via `setEnabled(false)`, I expect the second disable to have no effect.

**Actual behavior**
The second disable is "queued" up, such that I am forced to enable the window twice to get back to normal.

**To Reproduce**
In the electronquickstart repo, in main.js' `createWindow()`, add these lines:

    mainWindow.setEnabled(false);
    mainWindow.setEnabled(false);
    mainWindow.setEnabled(true);

The window will be disabled when launched. 

You see the same issue if you do it in reverse:

    mainWindow.setEnabled(true);
    mainWindow.setEnabled(false); // this doesn't actually disable it, because the window was enabled from the getgo

If this is expected behavior, can the [docs](https://github.com/electron/electron/blob/master/docs/api/browser-window.md#winsetenabledenable) be updated to explain this behavior.
atom/browser/native_window_views.cc
window_icon_ = base::win::ScopedHICON(CopyIcon(window_icon));
  app_icon_ = base::win::ScopedHICON(CopyIcon(app_icon));
  HWND hwnd = GetAcceleratedWidget();
  SendMessage(hwnd, WM_SETICON, ICON_SMALL,
              reinterpret_cast<LPARAM>(window_icon_.get()));
  SendMessage(hwnd, WM_SETICON, ICON_BIG,
              reinterpret_cast<LPARAM>(app_icon_.get()));
}
#elif defined(USE_X11)
void NativeWindowViews::SetIcon(const gfx::ImageSkia& icon) {
  auto* tree_host = static_cast<views::DesktopWindowTreeHost*>(
      views::DesktopWindowTreeHostX11::GetHostForXID(GetAcceleratedWidget()));
  tree_host->SetWindowIcons(icon, icon);
}
#endif
void NativeWindowViews::OnWidgetActivationChanged(views::Widget* changed_widget,
                                                  bool active) {
  if (changed_widget != widget())
    return;
  if (active)
    NativeWindow::NotifyWindowFocus();
  else
    NativeWindow::NotifyWindowBlur();
  
  if (!active && IsMenuBarAutoHide() && IsMenuBarVisible())
    SetMenuBarVisibility(false);
  root_view_->ResetAltState();
}
void NativeWindowViews::OnWidgetBoundsChanged(views::Widget* changed_widget,