Update webgl conformance test expectations for Mac Intel HD 3000 bots

BUG=225642,322795
TEST=gpu bots
TBR=kbr@chromium.org

Review URL: https://codereview.chromium.org/175403003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252602 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252602