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

src/effects/SkAlphaThresholdFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAlphaThresholdFilter.h"
 
 #include "SkBitmap.h"
@@ skipping 169 matching lines @@
         sk_sp<GrFragmentProcessor> fp(GrAlphaThresholdFragmentProcessor::Make(
                                                                    inputTexture.get(),
                                                                    maskTexture.get(),
                                                                    fInnerThreshold,
                                                                    fOuterThreshold,
                                                                    bounds));
         if (!fp) {
             return nullptr;
         }
 
-        return DrawWithFP(context, std::move(fp), bounds, source->internal_getProxy());
+        return DrawWithFP(context, std::move(fp), bounds);
     }
 #endif
 
     SkBitmap inputBM;
 
     if (!input->getROPixels(&inputBM)) {
         return nullptr;
     }
 
     if (inputBM.colorType() != kN32_SkColorType) {
@@ skipping 54 matching lines @@
                                                   (U8CPU)(SkColorGetG(source) * scale),
                                                   (U8CPU)(SkColorGetB(source) * scale));
                 }
             }
             dptr[y * dstWidth + x] = outputColor;
         }
     }
 
     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);
 }
 
 #ifndef SK_IGNORE_TO_STRING
 void SkAlphaThresholdFilterImpl::toString(SkString* str) const {
     str->appendf("SkAlphaThresholdImageFilter: (");
     str->appendf("inner: %f outer: %f", fInnerThreshold, fOuterThreshold);
     str->append(")");
 }
 #endif