Revert of change all factories to return their base-class

include/effects/SkMatrixConvolutionImageFilter.h

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkMatrixConvolutionImageFilter_DEFINED
 #define SkMatrixConvolutionImageFilter_DEFINED
 
@@ skipping 34 matching lines @@
                               offset of {1, 1}).
         @param tileMode       How accesses outside the image are treated.  (@see
                               TileMode).
         @param convolveAlpha  If true, all channels are convolved.  If false,
                               only the RGB channels are convolved, and
                               alpha is copied from the source image.
         @param input          The input image filter.  If NULL, the src bitmap
                               passed to filterImage() is used instead.
         @param cropRect       The rectangle to which the output processing will be limited.
     */
-    static SkImageFilter* Create(const SkISize& kernelSize,
-                                 const SkScalar* kernel,
-                                 SkScalar gain,
-                                 SkScalar bias,
-                                 const SkIPoint& kernelOffset,
-                                 TileMode tileMode,
-                                 bool convolveAlpha,
-                                 SkImageFilter* input = NULL,
-                                 const CropRect* cropRect = NULL);
+    static SkMatrixConvolutionImageFilter* Create(const SkISize& kernelSize,
+                                                  const SkScalar* kernel,
+                                                  SkScalar gain,
+                                                  SkScalar bias,
+                                                  const SkIPoint& kernelOffset,
+                                                  TileMode tileMode,
+                                                  bool convolveAlpha,
+                                                  SkImageFilter* input = NULL,
+                                                  const CropRect* cropRect = NULL);
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixConvolutionImageFilter)
 
 protected:
     SkMatrixConvolutionImageFilter(const SkISize& kernelSize,
                                    const SkScalar* kernel,
                                    SkScalar gain,
                                    SkScalar bias,
                                    const SkIPoint& kernelOffset,
@@ skipping 37 matching lines @@
                               SkBitmap* result,
                               const SkIRect& rect,
                               const SkIRect& bounds) const;
     void filterBorderPixels(const SkBitmap& src,
                             SkBitmap* result,
                             const SkIRect& rect,
                             const SkIRect& bounds) const;
 };
 
 #endif