COMP: Change threshold for TestParametricFunctions

Increase the threshold for image changes from 25 to 35 to accomodate
64-bit VS10.

Change-Id: I1ddccca2c04c494732a422ff2e419d5a64bce0ae
Merge topic 'Threshold_TestParameticFunctions' into master

3ac09a03 COMP: Change threshold for TestParametricFunctions