Updating test expectations for 2 WebGL tests.

Marking the following two WebGL tests as failing on Android:
conformance/glsl/misc/empty_main.vert.html
conformance/glsl/misc/gl_position_unset.vert.html

BUG=315976
R=kbr@chromium.org

Review URL: https://codereview.chromium.org/62683003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233478 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233478