PVS-Studio warning V567 for Chromium

int g_color_index = 0;

explicit ModalWindow(ui::ModalType modal_type) : ....
{
  ++g_color_index %= arraysize(g_colors);
  ....
}

This suspicious code was found in Chromium project by PVS-Studio static code analyzer.
Warning message is:
V567 Undefined behavior. The 'g_color_index' variable is modified while being used twice between sequence points. window_type_launcher.cc 60

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/