Fix the Skia roll - implement onWritePixels

Test: None

https://skia-review.googlesource.com/c/skia/+/105623 added a new
abstract method to SkSurface_Base, so these subclasses needs to
implement it. Implementation is empty just to get the roll fixed.

Change-Id: Ib6029acf40feb47a572cd6e18678b08a6f38fe4b