SF: Modify logic to handle "transparent Region" for displayFrame

sourceCrop and displayFrame calculations according to "transparent Region"
are not synchronized. Because of this mismatch scaling is introduced,
causing corruption in UI. To avoid this scaling, map displayFrame to
sourceCrop, apply reduce and remap result to displayFrame.

CRs-Fixed: 660699

Change-Id: I1e7ad5b1c8932413f53bb94a2e62895661b97057