ozone: gbm: Fix broken DCHECK if !OS_CHROMEOS
ozone: gbm: Fix broken DCHECK if !OS_CHROMEOS

This doesn't even compile:

../../base/logging.h:523:23: error: invalid operands to binary expression ('basic_ostream<char, std::char_traits<char> >' and 'gfx::BufferUsage')
  ss << names << " (" << v1 << " vs. " << v2 << ")";
  ~~~~~~~~~~~~~~~~~~~ ^  ~~

BUG=530712
TEST=cast_shell_linux tryjob with gbm enabled by default

Review URL: https://codereview.chromium.org/1346513002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#348784}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk