* 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
#include "atom/browser/web_contents_preferences.h"
#include "atom/browser/web_view_manager.h"
#include "atom/browser/window_list.h"
#include "atom/common/draggable_region.h"
#include "atom/common/native_mate_converters/image_converter.h"
#include "atom/common/options_switches.h"
#include "base/strings/utf_string_conversions.h"
#include "brightray/browser/inspectable_web_contents.h"
#include "brightray/browser/inspectable_web_contents_view.h"
#include "content/public/browser/browser_thread.h"
#include "native_mate/dictionary.h"
#include "ui/aura/window_tree_host.h"
#include "ui/base/hit_test.h"
#include "ui/gfx/image/image.h"
#include "ui/views/background.h"
#include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
#include "ui/views/controls/webview/webview.h"
#include "ui/views/widget/native_widget_private.h"
#include "ui/views/widget/widget.h"
#include "ui/views/window/client_view.h"
#include "ui/wm/core/shadow_types.h"
#include "ui/wm/core/window_util.h"
#if defined(USE_X11)
#include "atom/browser/browser.h"
#include "atom/browser/ui/views/frameless_view.h"
#include "atom/browser/ui/views/global_menu_bar_x11.h"
#include "atom/browser/ui/views/native_frame_view.h"
#include "atom/browser/ui/x/event_disabler.h"
#include "atom/browser/ui/x/window_state_watcher.h"
#include "atom/browser/ui/x/x_window_utils.h"