HWC 1.5: Add per-layer damage region

This adds an array of rects to hwc_layer_1_t that define which
portions of that layer's source buffer have been modified. If there
are a non-zero number of rects, then any portion of the source buffer
not touched by one of the rects may safely be assumed to not have
been modified. If no rects are defined, then the whole source buffer
must be assumed to have been modified.

Change-Id: Id5efafee74602ed7d76609180e334ed203c23f7e
2 files changed