* 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
const std::string& level,
                                       int relativeLevel,
                                       std::string* error) {
  bool level_changed = z_order != widget()->GetZOrderLevel();
  widget()->SetZOrderLevel(z_order);
#if defined(OS_WIN)
  
  behind_task_bar_ = false;
  if (z_order != ui::ZOrderLevel::kNormal) {
    
    
    static const std::vector<std::string> levels = {
        "floating", "torn-off-menu", "modal-panel", "main-menu", "status"};
    behind_task_bar_ = base::Contains(levels, level);
  }
#endif
  MoveBehindTaskBarIfNeeded();
  
  
  if (level_changed)
    NativeWindow::NotifyWindowAlwaysOnTopChanged();
}
ui::ZOrderLevel NativeWindowViews::GetZOrderLevel() {
  return widget()->GetZOrderLevel();
}
void NativeWindowViews::Center() {