Reviewed by Geoff.

        - fix http://bugs.webkit.org/show_bug.cgi?id=11132
          Caret disappears when you're typing

        * editing/SelectionController.cpp:
        (WebCore::SelectionController::setSelection): Remove unnecessary call to
        clearCaretRectIfNeeded. The recomputeCaretRect now takes care of this.
        (WebCore::SelectionController::recomputeCaretRect): Explicitly set m_needsLayout
        to false so we can get the old caret repaint rect. Later we need to change the
        design so getting the rect doesn't have a side effect of causing a layout without
        invalidation.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@16738 268f45cc-cd09-0410-ab3c-d52691b4dbfc