GitLab

This is similar idea which was already applied in png_codec.cc.
https://codereview.chromium.org/397673002/
(Sorry for making another review request.)

BUG=none
R=erg@chromium.org, sky@chromium.org, dcheng@chromium.org
TEST(DONE&PASSED)=gfx_unittests --gtest_filter="JPEGCodec*"

Review URL: https://codereview.chromium.org/404793004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284585 0039d316-1c4b-4281-b951-d872f2087c98