Algorithm to detect disjoint regions for gpu composition.

Algorithm to detect disjoint regions for gpu composition.

This algorithm traverse through x co-ordinates and at each
intersection of x co-ordinates, it will traverse through y
axis for intersections. At each y co-ordinate intersection
it will give out new layer with input layer ids active at
that point.

Jira: None.
Test: No graphics regressions on Linux and Android.

Signed-off-by: arpallet <avinash.reddy.palleti@intel.com>