remove dead methods now that we use specials exclusively for imagefilters

src/core/SkSpecialImage.h

Index: src/core/SkSpecialImage.h
diff --git a/src/core/SkSpecialImage.h b/src/core/SkSpecialImage.h
index 5dae05e245b85d07e891d98df20fd9ba6b0e7bd3..9afd64fa4539a9a578350a9f1a749b335e79f1f6 100644
--- a/src/core/SkSpecialImage.h
+++ b/src/core/SkSpecialImage.h
@@ -105,10 +105,6 @@ public:
      */
     sk_sp<SkImage> makeTightSubset(const SkIRect& subset) const;
 
-    // These three internal methods will go away (see skbug.com/4965)
-    bool internal_getBM(SkBitmap* result);
-    static sk_sp<SkSpecialImage> internal_fromBM(const SkBitmap&, const SkSurfaceProps*);
-
     // TODO: hide this when GrLayerHoister uses SkSpecialImages more fully (see skbug.com/5063)
     /**
      *  If the SpecialImage is backed by a gpu texture, return true.