Always use FrameNavigationDisabler during DocumentLoader detach.

BUG=617495

Review-Url: https://codereview.chromium.org/2079473002
Cr-Commit-Position: refs/heads/master@{#400558}
static NavigationType determineNavigationType(FrameLoadType frameLoadType, bool isFormSubmission, bool haveEvent)
{
    bool isReload = frameLoadType == FrameLoadTypeReload || frameLoadType == FrameLoadTypeReloadBypassingCache;
    bool isBackForward = isBackForwardLoadType(frameLoadType);
    if (isFormSubmission)
        return (isReload || isBackForward) ? NavigationTypeFormResubmitted : NavigationTypeFormSubmitted;
    if (haveEvent)
        return NavigationTypeLinkClicked;
    if (isReload)
        return NavigationTypeReload;
    if (isBackForward)
        return NavigationTypeBackForward;
    return NavigationTypeOther;
}

static NavigationType determineNavigationType(FrameLoadType frameLoadType, bool isFormSubmission, bool haveEvent)
{
    bool isReload = frameLoadType == FrameLoadTypeReload || frameLoadType == FrameLoadTypeReloadBypassingCache;
    bool isBackForward = isBackForwardLoadType(frameLoadType);
    if (isFormSubmission)
        return (isReload || isBackForward) ? NavigationTypeFormResubmitted : NavigationTypeFormSubmitted;
    if (haveEvent)
        return NavigationTypeLinkClicked;
    if (isReload)
        return NavigationTypeReload;
    if (isBackForward)
        return NavigationTypeBackForward;
    return NavigationTypeOther;
}
