The SkArithmeticMode_gpu GL filters support clamping to valid
premultiplied colors, however the flag for whether or not to do this,
which is present in their parent filters, is dropped when creating the
GL implementations. This change adds logic to forward the value from
the parent filter to the GL implementation.

This makes GPU behavior match software and fixes a WebKit
LayoutTest. See referenced bug.

BUG=473186

Review URL: https://codereview.chromium.org/1410553002
2 files changed