Input Method: rendering issues when composing text is wrapped.

Steps to reproduce:
1. Create a TextArea, set "wrapText" to true.
2. Turn on Chinese or Japanese input method.
3. Input long composing text to make it's wrapped.

Issues:
1. the dot-line of the wrapped composing text is separated from the text. (wrap-composing-text.png)
2. the choices window is not moved when the composing text is wrapped, so they are overlapped. (choices-window.png)