Reviewed by Chris Blumenberg.

    Reviewed by Chris Blumenberg.

        - some refactoring cleanup in the selection/searching code

        * Misc.subproj/WebSearchableTextView.h:
        moved WebDocumentSelection protocol conformation to this class, was in subclass WebTextView
        * Misc.subproj/WebSearchableTextView.m:
        (-[WebSearchableTextView selectionRect]):
        new method (moved here from Safari) to return a single rect encompassing all selected text
        (-[WebSearchableTextView pasteboardTypesForSelection]):
        moved here from WebTextView
        (-[WebSearchableTextView writeSelectionWithPasteboardTypes:toPasteboard:]):
        ditto

        * WebView.subproj/WebDocumentInternal.h:
        moved WebDocumentSelection protocol out of here

        * WebView.subproj/WebDocumentPrivate.h:
        moved WebDocumentSelection protocol into here, added selectionRect method

        * WebView.subproj/WebHTMLView.m:
        (-[WebHTMLView selectionRect]):
        new method, calls existing bridge method formerly called by _selectionRect
        (-[WebHTMLView _selectionRect]):
        now calls [self selectionRect]. We can't just delete _selectionRect because it's used by Mail.

        * WebView.subproj/WebHTMLViewPrivate.h:
        removed _selectionRect since it's in WebDocumentSelection now

        * WebView.subproj/WebTextView.h:
        removed WebDocumentSelection from protocol list since it's in superclass now

        * WebView.subproj/WebTextView.m:
        removed old WebDocumentSelection methods because they are in superclass now

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@9820 268f45cc-cd09-0410-ab3c-d52691b4dbfc