Begin removing deprecated (and now, unused) ImageFilter code paths

This CL focuses on removing the Proxy objects but takes some other stuff with it.

BUG=skia:4965
TBR=reed@google.com

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1896383003

Review URL: https://codereview.chromium.org/1896383003
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index 1f22a6e..d5a048c 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -533,8 +533,7 @@
         srcTexture.reset(scratch);
     }
 
-    return SkSpecialImage::MakeFromGpu(input->internal_getProxy(),
-                                       SkIRect::MakeWH(rect.width(), rect.height()),
+    return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(rect.width(), rect.height()),
                                        kNeedNewImageUniqueID_SpecialImage,
                                        srcTexture, &input->props());
 }
@@ -644,7 +643,6 @@
     offset->fX = bounds.left();
     offset->fY = bounds.top();
 
-    return SkSpecialImage::MakeFromRaster(source->internal_getProxy(),
-                                          SkIRect::MakeWH(bounds.width(), bounds.height()),
+    return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(bounds.width(), bounds.height()),
                                           dst, &source->props());
 }