there is already a shared XPath test class

Change-Id: I3c94d1f8302aba52164fb27f40832415eb435a85
use the shared XPath test code in chart2

Change-Id: Ia8481516eb3d53f406824cc2ef8873fe1cba3909
one more simplification

Change-Id: I9aaf67872dde324f403598a7361cd4eda60b82b0