Revert of factories should return baseclass, allowing the impl to specialize

src/effects/SkTileImageFilter.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 "SkTileImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 #include "SkShader.h"
 #include "SkValidationUtils.h"
 
-SkImageFilter* SkTileImageFilter::Create(const SkRect& srcRect, const SkRect& dstRect,
-                                         SkImageFilter* input) {
+SkTileImageFilter* SkTileImageFilter::Create(const SkRect& srcRect, const SkRect& dstRect,
+                                             SkImageFilter* input) {
     if (!SkIsValidRect(srcRect) || !SkIsValidRect(dstRect)) {
         return nullptr;
     }
     return new SkTileImageFilter(srcRect, dstRect, input);
 }
 
 bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                       const Context& ctx,
                                       SkBitmap* dst, SkIPoint* offset) const {
     SkBitmap source = src;
@@ skipping 90 matching lines @@
     str->appendf(" dst: %.2f %.2f %.2f %.2f",
                  fDstRect.fLeft, fDstRect.fTop, fDstRect.fRight, fDstRect.fBottom);
     if (this->getInput(0)) {
         str->appendf("input: (");
         this->getInput(0)->toString(str);
         str->appendf(")");
     }
     str->append(")");
 }
 #endif