factories should return baseclass, allowing the impl to specialize

include/effects/SkTileImageFilter.h

Index: include/effects/SkTileImageFilter.h
diff --git a/include/effects/SkTileImageFilter.h b/include/effects/SkTileImageFilter.h
index 4dccf852be90ee9162f63ea1047e20d7b465cc84..a2a1bb0fe1323cff144f394d6d3cc82b71a67c56 100644
--- a/include/effects/SkTileImageFilter.h
+++ b/include/effects/SkTileImageFilter.h
@@ -15,12 +15,11 @@ class SK_API SkTileImageFilter : public SkImageFilter {
 
 public:
     /** Create a tile image filter
-        @param srcRect  Defines the pixels to tile
-        @param dstRect  Defines the pixels where tiles are drawn
+        @param src  Defines the pixels to tile
+        @param dst  Defines the pixels where tiles are drawn
         @param input    Input from which the subregion defined by srcRect will be tiled
     */
-    static SkTileImageFilter* Create(const SkRect& srcRect, const SkRect& dstRect,
-                                     SkImageFilter* input);
+    static SkImageFilter* Create(const SkRect& src, const SkRect& dst, SkImageFilter* input);
 
     bool onFilterImage(Proxy* proxy, const SkBitmap& src, const Context& ctx,
                        SkBitmap* dst, SkIPoint* offset) const override;
@@ -32,12 +31,12 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTileImageFilter)
 
 protected:
-    SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input)
-        : INHERITED(1, &input, NULL), fSrcRect(srcRect), fDstRect(dstRect) {}
-
     void flatten(SkWriteBuffer& buffer) const override;
 
 private:
+    SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input)
+        : INHERITED(1, &input, NULL), fSrcRect(srcRect), fDstRect(dstRect) {}
+
     SkRect fSrcRect;
     SkRect fDstRect;
 };