Do an early return from GLES2DecoderImpl::Initialize if context group initialization fails.
Do an early return from GLES2DecoderImpl::Initialize if context group initialization fails.

BUG=none
TEST=run GPU process under valgrind on a machine w/no GPU


Review URL: http://codereview.chromium.org/5181002

git-svn-id: http://src.chromium.org/svn/trunk/src@66489 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 973d2477424395d0e4a2afc6a31e9c9cd78700f3
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser