SkShader::asNewEffect Refactoring

The new signature is:

	bool asNewEffect(GrContext* context, const SkPaint& paint, GrColor* grColor, GrEffectRef** grEffect, const SkMatrix* localMatrixOrNull) const;

It will fix the hack for skcolorshader by modifying the GrColor parameter in SkGr::SkPaint2GrPaintShader.

BUG=skia:2646
R=jvanverth@google.com, bsalomon@google.com

Author: dandov@google.com

Review URL: https://codereview.chromium.org/318923005
25 files changed