Inject some log messages to understand when a rare random crash happens.

This happens in the webgl lose context only, so should not affect any perf.

Will revert after we gather the information we need.

BUG=374378
TEST=
TBR=kbr@chromium.org

Review URL: https://codereview.chromium.org/347653004

git-svn-id: svn://svn.chromium.org/blink/trunk@176554 bbb929c8-8fbe-4397-9dbb-9b2b20218538