Reland of change all factories to return their base-class

include/effects/SkCornerPathEffect.h

Index: include/effects/SkCornerPathEffect.h
diff --git a/include/effects/SkCornerPathEffect.h b/include/effects/SkCornerPathEffect.h
index 4c8908575db241f581e3c9f6e5fd857f69f7cdfb..13095f0e6c4a46cb46d6db731a2707f967576d0d 100644
--- a/include/effects/SkCornerPathEffect.h
+++ b/include/effects/SkCornerPathEffect.h
@@ -20,8 +20,7 @@
     /** radius must be > 0 to have an effect. It specifies the distance from each corner
         that should be "rounded".
     */
-    static SkCornerPathEffect* Create(SkScalar radius) { return new SkCornerPathEffect(radius); }
-    virtual ~SkCornerPathEffect();
+    static SkPathEffect* Create(SkScalar radius) { return new SkCornerPathEffect(radius); }
 
     virtual bool filterPath(SkPath* dst, const SkPath& src,
                             SkStrokeRec*, const SkRect*) const override;
@@ -34,6 +33,8 @@
 #endif
 
 protected:
+    virtual ~SkCornerPathEffect();
+
     explicit SkCornerPathEffect(SkScalar radius);
     void flatten(SkWriteBuffer&) const override;