Reviewed by Eric Seidel.

        [chromium] font fallback for generic fonts picks wrong font
        https://bugs.webkit.org/show_bug.cgi?id=37033

        When a page specifies the generic "monospace" font and the user's
        browser-configured monospace font doesn't exist, we previously relied
        on getLastResortFallbackFont to eventually pick a monospace font for us.

        But that doesn't quite work: WebKit first falls back to the user's
        "preferred standard font" before hitting the last resort code path.
        So if the above conditions hold but this font exists, we'll end up
        never hitting the last resort codepath.

        The fix is to allow OS-level font fallback when first attempting to
        resolve monospace.  The existing code tried to do this, but the logic
        was wrong.  We would eventually fall back to the correct font anyway
        so we didn't notice the logic was wrong.

        This code is all handling cases where particular fonts aren't installed,
        so I can't think of a way to test it; existing tests should still pass.

        * platform/graphics/chromium/FontCacheLinux.cpp:
        (WebCore::FontCache::createFontPlatformData):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@57027 268f45cc-cd09-0410-ab3c-d52691b4dbfc