Revert 255386 "Support ARGB_8888 by default in GLHelperReadbackS..."

This seems to have broken the pixel tests on the Android GPU bot.

> Support ARGB_8888 by default in GLHelperReadbackSupport
> 
> This is a work around for a driver bug on Galaxy Nexus
> 
> BUG=349667
> 
> Review URL: https://codereview.chromium.org/184103037

TBR=clholgat@chromium.org
BUG=349667,350043

Review URL: https://codereview.chromium.org/179793010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255420 0039d316-1c4b-4281-b951-d872f2087c98
Revert 255228 "Don't blacklist accelerated 2d canvas if WinStats..."

There is built-in logic to ignore a blacklist entry if related data is unavailable, so this CL doesn't have any effects.

> Don't blacklist accelerated 2d canvas if WinStats are unavailable.
> 
> BUG=349628
> TEST=gpu_unittests
> R=kbr@chromium.org
> 
> Review URL: https://codereview.chromium.org/183883026

TBR=zmo@chromium.org

Review URL: https://codereview.chromium.org/180723020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255421 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255421