* 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
return content_view() ? content_view()->GetBoundsInScreen() : gfx::Rect();
}
gfx::Size NativeWindowViews::GetContentSize() {
#if defined(OS_WIN)
  if (IsMinimized())
    return NativeWindow::GetContentSize();
#endif
  return content_view() ? content_view()->size() : gfx::Size();
}
gfx::Rect NativeWindowViews::GetNormalBounds() {
  return widget()->GetRestoredBounds();
}
void NativeWindowViews::SetContentSizeConstraints(
    const extensions::SizeConstraints& size_constraints) {
  NativeWindow::SetContentSizeConstraints(size_constraints);
#if defined(OS_WIN)
  
  
  if (!thick_frame_)
    return;
#endif
  
  
  if (widget() && widget()->widget_delegate())
    widget()->OnSizeConstraintsChanged();
  if (resizable_)
    old_size_constraints_ = size_constraints;
}
void NativeWindowViews::SetResizable(bool resizable) {