toDataURL on zero-size canvas returns 'data:,'
Actual output:
FAIL (fallback content)
Harness status: OK
Found 1 tests
assert_equals("data:,", "data:,", "data === 'data:,' (got data:,[string], expected data:,[string])") at _assertSame ( /html/canvas/resources/canvas-tests.js:17:5)