Mark virtual/gpu/fast/canvas/canvas-composite-image.html slow.
Mark virtual/gpu/fast/canvas/canvas-composite-image.html slow.

BUG=433711

Review URL: https://codereview.chromium.org/743183003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@185689 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs