Reviewed by Dave Hyatt.

    Reviewed by Dave Hyatt.

        - fixed these bugs:
        <rdar://problem/4118510> Textareas with a vertical scroll bar should have their resize corner under the scroll bar
        <rdar://problem/4118523> Resize image in textareas is drawn repeatedly when scrolling vertically with scrollbar

        Test cases added: none; doesn't affect page layout

        * kwq/KWQTextArea.h:
        added inInitWithFrame ivar
        * kwq/KWQTextArea.mm:
        (+[KWQTextArea _resizeCornerImage]):
        moved here from KWQTextAreaTextView; now it's a class method so we only look up the image once.
        (-[KWQTextArea initWithFrame:]):
        set and clear inInitWithFrame ivar, used by -tile
        (-[KWQTextArea _isResizableByUser]):
        renamed with an underscore for consistency
        (-[KWQTextArea _textViewShouldHandleResizing]):
        new method, returns YES if the textarea is user-resizable and the enclosed textview is responsible for drawing
        and tracking the resize corner.
        (-[KWQTextArea tile]):
        shrink the vertical scroller if appropriate to account for the resize corner
        (-[KWQTextArea _resizeCornerRect]):
        new method, returns the bottom-right corner rect, where the resize image goes
        (-[KWQTextArea _trackResizeFromMouseDown:]):
        moved here from KWQTextAreaTextView. The only changes were to move the [NSCursor set] call inside here (was in
        the caller), and to use self where it was using [self _enclosingTextArea], and to move a comment in here that
        was in the caller
        (-[KWQTextArea mouseDown:]):
        track resizing if appropriate
        (-[KWQTextArea drawRect:]):
        draw the resize corner if appropriate
        (-[KWQTextAreaTextView _resizeCornerRect]):
        get the resize image from KWQTextArea
        (-[KWQTextAreaTextView resetCursorRects]):
        check _textViewShouldHandleResizing
        (-[KWQTextAreaTextView drawRect:]):
        ditto
        (-[KWQTextAreaTextView mouseDown:]):
        ditto; also, make the textarea handle the resize tracking now

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@9210 268f45cc-cd09-0410-ab3c-d52691b4dbfc