Remove asTextureRef from SkSpecialImage & update effects accordingly (take 2)

This CL also renames SkSpecialImage::asTextureProxy to asTextureProxyRef

This is a reland of: https://skia-review.googlesource.com/c/7995/ (Remove asTextureRef from SkSpecialImage & update effects accordingly)

It should be good to land since https://skia-review.googlesource.com/c/8701/ (Replace SkSpecialImage::makeTightSubset with asImage (take 2)) fixes the Chrome-side issue

Change-Id: I3d88b2b3d23fd69f3fb914a69dacca96cbc038a4
Reviewed-on: https://skia-review.googlesource.com/8450
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index bf92b4f..9ac69d3 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -477,7 +477,7 @@
                                           GrMorphologyEffect::MorphologyType morphType,
                                           SkISize radius,
                                           const SkImageFilter::OutputProperties& outputProperties) {
-    sk_sp<GrTextureProxy> srcTexture(input->asTextureProxy(context));
+    sk_sp<GrTextureProxy> srcTexture(input->asTextureProxyRef(context));
     SkASSERT(srcTexture);
     sk_sp<SkColorSpace> colorSpace = sk_ref_sp(outputProperties.colorSpace());
     GrPixelConfig config = GrRenderableConfigForColorSpace(colorSpace.get());