stop passing |level| to WebGraphicsContext3D

|level| is no longer used as a result of crbug.com/443151.
So currently video canvas painting is broken as the call has an empty implementation.

BUG=485482

Review URL: https://codereview.chromium.org/1138343004

Cr-Commit-Position: refs/heads/master@{#329533}
1 file changed