Avoids uploading levels other than 0 for incomplete textures.

TRAC #21815

Fixes compressed texture test assertion in WebGL top-of-tree conformance suite when running with debug build

Signed-off-by: Daniel Koch
Signed-off-by: Nicolas Capens

git-svn-id: http://angleproject.googlecode.com/svn/trunk@1323 736b8ea6-26fd-11df-bfd4-992fa37f6226
3 files changed