void RenderFlowThread::clearRenderObjectCustomStyle(const RenderObject* object,
    const RenderRegion* oldStartRegion, const RenderRegion* oldEndRegion,
    const RenderRegion* newStartRegion, const RenderRegion* newEndRegion)
{
    // Clear the styles for the object in the regions.
    // The styles are not cleared for the regions that are contained in both ranges.
    bool insideOldRegionRange = false;
    bool insideNewRegionRange = false;
    for (RenderRegionList::iterator iter = m_regionList.begin(); iter != m_regionList.end(); ++iter) {
        RenderRegion* region = *iter;

        if (oldStartRegion == region)
            insideOldRegionRange = true;
        if (newStartRegion == region)
            insideNewRegionRange = true;

        if (!(insideOldRegionRange && insideNewRegionRange))
            region->clearObjectStyleInRegion(object);

        if (oldEndRegion == region)
            insideOldRegionRange = false;
        if (newEndRegion == region)
            insideNewRegionRange = false;
    }
}