DON'T MERGE: the viewport doesn't get set otherwise?

When writing the tiled rendering test, asserts were firing because the
redraw area wasn't set on the page -- however I don't understand
things well enought yet to know whether or not this is the correct
solution.. (Especially as this happened only for certain tile configurations.)

Change-Id: I187d639b00d0748e7cc9fd6cc33d555f02f9a081
Add LOK tiled rendering divided-tile unit test.

I.e. we render the same area as one larger tile, and then
as 4 sub-tiles (which, when put together, should be identical
to the larger tile). However currently only the top-left sub-tile
actually matches the larger tile, so we have to disable the test
for the remaining sub-tiles.

Change-Id: If1130022b43898e20fefff3e9f592102da3e413a
Add LOK and tiledrendering log areas.

Change-Id: I885acc9b4a52835fa256c2ecd1b8da917b4f7ba7
LOK: some logging for tiled rendering.

Change-Id: I5779eec97507b1996cda89174a6e6c55cdd57baf