The ANGLETest::TearDown() call was set at the beginning of the
function where as it should be at the end since it destroys the
context. The earlier version would not cause any crashes because the
GL function calls would be ignored.

BUG=angleproject:1445

TEST=angle_end2end_tests

Change-Id: I187cb8fede1db4ef2bfc13ab850594c41e00b0b0
Reviewed-on: https://chromium-review.googlesource.com/362220Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>