Reviewed by Ojan Vafai.

        Inserting multiple whitespace using text composition (IME) should insert interleaved nbsp and whitespace.
        https://bugs.webkit.org/show_bug.cgi?id=52781

        The test was rebaselined to have interleaved space and non-breaking space.

        * editing/inserting/insert-composition-whitespace-expected.txt:
        * editing/inserting/insert-composition-whitespace.html:
2011-01-24  Ryosuke Niwa  <rniwa@webkit.org>

        Reviewed by Ojan Vafai.

        Inserting multiple whitespace using text composition (IME) should insert interleaved nbsp and whitespace.
        https://bugs.webkit.org/show_bug.cgi?id=52781

        The bug was caused by stringWithRebalancedWhitespace's replacing the space at the beginning of a paragraph
        and the end of a paragraph by a non-breaking space after it replaced two consecutive spaces by a space and
        non-breaking space pattern, thereby replacing more spaces by non-breaking spaces than needed.

        Rewrote the function using Vector<UChar> to fix the bug. New function no longer calls String::replace
        multiple times but instead it traverses through the string and replaces a space that immediately follows
        another space or appears at the beginning of a paragraph or at the end of a paragraph by a non-break space.

        * editing/CompositeEditCommand.cpp:
        * editing/htmlediting.cpp:
        (WebCore::stringWithRebalancedWhitespace): Written.
        * editing/htmlediting.h:
        (WebCore::isWhitespace): Removed from CompositeEditCommand.cpp


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@76565 268f45cc-cd09-0410-ab3c-d52691b4dbfc