Support projection of DisplayLists onto ancestors.

For now, ancestor views signal the acceptance of projections with a
save(0x20)/restore pair.

During the order traversal, each view with the save(0x20) code will
collect descendent views with mProjectToContainedVolume (which still
needs to be renamed) so that they can be drawn out of order later.

- *Temporary* sample code added to HwAccelerationTest.

- Note that a projected displaylist must not be clipped.

Change-Id: I45c493e845961535b958d59c53e8aff3f8891d9f