Reviewed by Adam Roben

    Reviewed by Adam Roben

        - fixes <rdar://problem/4804614> Bad grammar ranges are not visibly marked

        This patch introduces much of the guts of grammar checking, though still not enough to actually
        check grammar sensibly, due to:

        <rdar://problem/4811175> Many false reports of bad grammar appear, caused by insufficient
        context passed to grammar checker

        * platform/Logging.h:
        * platform/Logging.cpp:
        new log channel SpellingAndGrammar

        * bridge/mac/WebCorePageBridge.mm:
        (initializeLoggingChannelsIfNecessary):
        initialize new log channel

        * bridge/mac/FrameMac.mm:
        (WebCore::FrameMac::advanceToNextMisspelling):
        Compute bad grammar range when computing misspelling range. Find first detailed grammar range from the
        set NSSpellChecker determines. Compare it with misspelling range to see which is earliest (or shortest
        in the event of a tie), and do further processing with that one (select range; create marker that
        causes range to be visibly marked with a funky underline; update spelling panel appropriately).
        (WebCore::FrameMac::markMisspellings):
        More or less the same types of changes as in advanceToNextMisspelling The loops are structured just
        differently enough to make sharing code between these two functions a little tricky, so I decided to
        save that for a later patch.

        (WebCore::FrameMac::respondToChangedSelection):
        remove grammar markers when we remove spelling markers

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@17476 268f45cc-cd09-0410-ab3c-d52691b4dbfc