Better feedback on maps GPU test for out-of-range errors

BUG=143317
TBR=kbr@chromium.org

Review URL: https://codereview.chromium.org/80953004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236605 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236605
Blink roll 162469:162483

http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=162470:162483&mode=html
TBR=
BUG=

Review URL: https://codereview.chromium.org/81183004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236606 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236607 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236607