PROBLEM STATEMENT:
ToolStripSplitButton is constructed by a "Push Button" and a "Toggle Button", but when you brows its children's size, both of the "Button"s are the same one

REPRODUCE:
1. start up uia2atk/test/samples/toolstripsplitbutton.py and accerciser
2. navigate from "ipy" -> "ToolStrip" -> 10
3. double click the "push button" and "toggle button", you will notice the red rectangle navigate at the same position

RESULTS:
the size of push button and toggle button are the same, you could see its position value at AtkComponent from Interface Viewer tab of Accerciser.

EXPECTED RESULTS:
the push button's size and toggle button's size is different, and the red rectangle navigate to different position