2010-01-22 Maciej Stachowiak <mjs@apple.com>

2010-01-22  Maciej Stachowiak  <mjs@apple.com>

        Reviewed by Adam Roben.

        Use stale cache data when going back and forward but not using WebCore’s page cache
        https://bugs.webkit.org/show_bug.cgi?id=33993
        <rdar://problem/7383392>

        No tests since this is a performance change.

        * loader/CachePolicy.h:
        (WebCore::): Add CachePolicyAllowStale.
        * loader/DocLoader.cpp:
        (WebCore::DocLoader::checkForReload): Never reload in the case of
        CachePolicyAllowStale.
        * loader/FrameLoader.cpp:
        (WebCore::FrameLoader::subresourceCachePolicy): Return CachePolicyAllowStale
        if the main resource is being loaded to allow stale data.
        (WebCore::FrameLoader::addExtraFieldsToRequest): Use ReturnCacheDataElseLoad
        on back/forward loads - needed when going back of forward to a page with frames.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@53737 268f45cc-cd09-0410-ab3c-d52691b4dbfc