Untainted canvas:
PASS: Calling readPixels() from an untainted canvas was allowed.
PASS: Calling toDataURL() on an untainted canvas was allowed.


Tainted canvas:
PASS: Calling texImage2D() with a tainted image was not allowed: Threw error: Error: SecurityError: DOM Exception 18.
PASS: Calling readPixels() on a canvas where tainting was attempted by a remote image was allowed.
PASS: Calling toDataURL() on a canvas where tainting was attempted by a remote image was allowed.
PASS: Calling texImage2D() with a tainted canvas was not allowed: Threw error: Error: SecurityError: DOM Exception 18.
PASS: Calling readPixels() on a canvas where tainting was attempted by a tainted canvas was allowed.
PASS: Calling toDataURL() on a canvas where tainting was attempted by a tainted canvas was allowed.