factories should return baseclass, allowing the impl to specialize

include/effects/SkMorphologyImageFilter.h

Index: include/effects/SkMorphologyImageFilter.h
diff --git a/include/effects/SkMorphologyImageFilter.h b/include/effects/SkMorphologyImageFilter.h
index 8d17609e5fda3d96c42b5bf11ac046ec0e4e7b98..c927f22e724f937623772382a791a69c1da21824 100644
--- a/include/effects/SkMorphologyImageFilter.h
+++ b/include/effects/SkMorphologyImageFilter.h
@@ -13,7 +13,7 @@
 #include "SkImageFilter.h"
 #include "SkSize.h"
 
-class SK_API SkMorphologyImageFilter : public SkImageFilter {
+class SkMorphologyImageFilter : public SkImageFilter {
 public:
     void computeFastBounds(const SkRect& src, SkRect* dst) const override;
     bool onFilterBounds(const SkIRect& src, const SkMatrix& ctm, SkIRect* dst) const override;
@@ -51,9 +51,8 @@ private:
 
 class SK_API SkDilateImageFilter : public SkMorphologyImageFilter {
 public:
-    static SkDilateImageFilter* Create(int radiusX, int radiusY,
-                                       SkImageFilter* input = NULL,
-                                       const CropRect* cropRect = NULL) {
+    static SkImageFilter* Create(int radiusX, int radiusY, SkImageFilter* input = NULL,
+                                 const CropRect* cropRect = NULL) {
         if (radiusX < 0 || radiusY < 0) {
             return NULL;
         }
@@ -62,6 +61,7 @@ public:
 
     bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                        SkBitmap* result, SkIPoint* offset) const override;
+
 #if SK_SUPPORT_GPU
     bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const Context&,
                         SkBitmap* result, SkIPoint* offset) const override;
@@ -70,16 +70,16 @@ public:
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDilateImageFilter)
 
-protected:
+private:
     SkDilateImageFilter(int radiusX, int radiusY, SkImageFilter* input, const CropRect* cropRect)
         : INHERITED(radiusX, radiusY, input, cropRect) {}
-private:
+
     typedef SkMorphologyImageFilter INHERITED;
 };
 
 class SK_API SkErodeImageFilter : public SkMorphologyImageFilter {
 public:
-    static SkErodeImageFilter* Create(int radiusX, int radiusY,
+    static SkImageFilter* Create(int radiusX, int radiusY,
                                       SkImageFilter* input = NULL,
                                       const CropRect* cropRect = NULL) {
         if (radiusX < 0 || radiusY < 0) {
@@ -90,6 +90,7 @@ public:
 
     bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                        SkBitmap* result, SkIPoint* offset) const override;
+
 #if SK_SUPPORT_GPU
     bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const Context&,
                         SkBitmap* result, SkIPoint* offset) const override;
@@ -98,11 +99,10 @@ public:
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkErodeImageFilter)
 
-protected:
+private:
     SkErodeImageFilter(int radiusX, int radiusY, SkImageFilter* input, const CropRect* cropRect)
         : INHERITED(radiusX, radiusY, input, cropRect) {}
 
-private:
     typedef SkMorphologyImageFilter INHERITED;
 };