debugd: add drm vblank events to systrace

Add drm::drm_vblank_event to gfx events.

BUG=chromium-os:17379 chromium:118032
TEST=collect trace and check contents

Change-Id: I36e83c145c7a53e071d88a8af20f48941a93929e
1 file changed
tree: fcfcbc4712bf711a9cfbb6b06fc42d2920a99f3a
  1. .gitignore
  2. Makefile
  3. OWNERS
  4. README
  5. doc/
  6. share/
  7. src/