Remove deprecated SkSurface::prepareForExternalIO and related uses of the name.

In a future CL I intend to use prepareForExternalIO to be a specific operation
to do to an SkSurface/SkImage so this is a pre CL that removes our use of that
phrase when related to flushing.

Bug: skia:8802
Change-Id: I3efe4c4061fe962e2fc1339185feb5ded6e23005
Commit-Queue: Brian Salomon <>
Commit-Queue: Greg Daniel <>
Reviewed-by: Brian Salomon <>
13 files changed