Remove declaration of surfaceFillContext

The implementation of skgpu::v2::Device::surfaceFillContext() was
recently removed, also remove its declaration to revent link time
errors.

Change-Id: I2c2d7673e9bb824d79c47c4e00423c63228c9161
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437120
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
1 file changed