When unpack parameters are set so that rows being read overlap in
the unpack buffer stored in GPU memory, NVIDIA GL driver may not
upload the last pixels of the last one or more rows of a texture. The
driver may also crash when the amount of overlap is high.

This issue affects both TexImage* and TexSubImage* calls.

Work around the issue by uploading textures row by row when the rows
being read overlap in the unpack buffer. The workaround could possibly
be optimized by uploading several of the first rows with a single call
in some cases where the amount of overlap is low, but this is expected
to be a rarely used corner case, so the added complexity that the
optimization would create seems like a bad tradeoff.

The issue does not seem to be triggered when the layers (images) of a
3D texture overlap, as long as the rows inside the images don't.

The workaround has been ported from Chromium.

This patch adds setting dirty bits when unpack state is set in
StateManagerGL.

The included test case also reveals some issue in the D3D backend, but
this is left to be addressed later.

BUG=angleproject:1376
TEST=angle_end2end_tests

Change-Id: I7dbe73ebb70bbbc284fa92381546f4f2f832d333
Reviewed-on: https://chromium-review.googlesource.com/346430Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>