* Electron Version: 2.0.0
* Operating System (Platform and Version): Windows 10
* Last known working Electron version: before commit bb5eecc16cff8053c7b04e0b9396803fbbb8c4df

**Expected Behavior**
Width and height of a window should not change while being dragged 

**Actual behavior**
Width and height become smaller.

**To Reproduce**
Create a window with:
  var mainWindow = new BrowserWindow({width: 1024, height: 880, x: 30, y: 30,
            resizable: false })

Then drag the window.  Width and height become smaller than specified (1024, 880)

**Additional Information**
NativeWindowViews::SetBounds calls SetMin/MaxSize(bounds) when resizable_ is false.  bounds get adjusted to smaller  numbers by WindowBoundsToContentBounds.

shell/browser/native_window_views.cc
if (IsVisible())
    widget()->Maximize();
  else
    widget()->native_widget_private()->Show(ui::SHOW_STATE_MAXIMIZED,
                                            gfx::Rect());
}
#endif
void NativeWindowViews::Unmaximize() {
#if defined(OS_WIN)
  if (!(::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_THICKFRAME)) {
    SetBounds(restore_bounds_, false);
    return;
  }
#endif
  widget()->Restore();
}
bool NativeWindowViews::IsMaximized() {
  return widget()->IsMaximized();
}
void NativeWindowViews::Minimize() {
  if (IsVisible())
    widget()->Minimize();
  else
    widget()->native_widget_private()->Show(ui::SHOW_STATE_MINIMIZED,
                                            gfx::Rect());
}
void NativeWindowViews::Restore() {