* 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 "base/strings/string_util.h"
#include "chrome/browser/ui/libgtkui/unity_service.h"
#include "ui/base/x/x11_util.h"
#include "ui/gfx/x/x11_types.h"
#include "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
#include "ui/views/window/native_frame_view.h"
#elif defined(OS_WIN)
#include "atom/browser/ui/views/win_frame_view.h"
#include "atom/browser/ui/win/atom_desktop_native_widget_aura.h"
#include "atom/browser/ui/win/atom_desktop_window_tree_host_win.h"
#include "skia/ext/skia_utils_win.h"
#include "ui/base/win/shell.h"
#include "ui/display/display.h"
#include "ui/display/screen.h"
#include "ui/display/win/screen_win.h"
#include "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
#endif
namespace atom {
namespace {
#if defined(OS_WIN)
void FlipWindowStyle(HWND handle, bool on, DWORD flag) {
  DWORD style = ::GetWindowLong(handle, GWL_STYLE);
  if (on)
    style |= flag;
  else
    style &= ~flag;
  ::SetWindowLong(handle, GWL_STYLE, style);
}
#endif
class NativeWindowClientView : public views::ClientView {