Now that all creation of SkImageFilters goes through
factory Create() methods, there's no real reason for the
convenience constructors. Some SkImageFilter subclasses
which actually have zero DAG-able inputs were passing NULL
to the superclass constructor. This actually means 1 input,
with a NULL value, not zero inputs. This becomes more
relevant for the upcoming cache infrastructure, where this
indicates that the filter will use its src input, where in
fact some of these filters do not (they are image generators
only).
Limiting SkImageFilter to a single constructor resolves this
ambiguity.
Along the way, I removed all of the default parameters to
the constructors, since the Create methods always call them
with the full argument list.
BUG=skia:
R=reed@google.com
Author: senorblanco@chromium.org
Review URL: https://codereview.chromium.org/376953003
9ea3d57fde