Update SkMergeImageFilter to sk_sp

src/effects/SkDropShadowImageFilter.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 "SkDropShadowImageFilter.h"
 
 #include "SkBlurImageFilter.h"
@@ skipping 19 matching lines @@
 SkFlattenable* SkDropShadowImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     SkScalar dx = buffer.readScalar();
     SkScalar dy = buffer.readScalar();
     SkScalar sigmaX = buffer.readScalar();
     SkScalar sigmaY = buffer.readScalar();
     SkColor color = buffer.readColor();
     ShadowMode shadowMode = buffer.isVersionLT(SkReadBuffer::kDropShadowMode_Version) ?
                             kDrawShadowAndForeground_ShadowMode :
                             static_cast<ShadowMode>(buffer.readInt());
-    return Create(dx, dy, sigmaX, sigmaY, color, shadowMode, common.getInput(0),
+    return Create(dx, dy, sigmaX, sigmaY, color, shadowMode, common.getInput(0).get(),
                   &common.cropRect());
 }
 
 void SkDropShadowImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fDx);
     buffer.writeScalar(fDy);
     buffer.writeScalar(fSigmaX);
     buffer.writeScalar(fSigmaY);
     buffer.writeColor(fColor);
@@ skipping 103 matching lines @@
         "kDrawShadowAndForeground", "kDrawShadowOnly"
     };
 
     static_assert(kShadowModeCount == SK_ARRAY_COUNT(gModeStrings), "enum_mismatch");
 
     str->appendf(" mode: %s", gModeStrings[fShadowMode]);
 
     str->append(")");
 }
 #endif