Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.

src/effects/SkOffsetImageFilter.cpp

Index: src/effects/SkOffsetImageFilter.cpp
diff --git a/src/effects/SkOffsetImageFilter.cpp b/src/effects/SkOffsetImageFilter.cpp
index 90528c62d80eb1312f676d4fa02718969c17986b..b7ded082d9c3b462471cbe5f9eeea05c9839b2eb 100644
--- a/src/effects/SkOffsetImageFilter.cpp
+++ b/src/effects/SkOffsetImageFilter.cpp
@@ -108,12 +108,3 @@ SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter
   : INHERITED(1, &input, cropRect, uniqueID) {
     fOffset.set(dx, dy);
 }
-
-#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
-SkOffsetImageFilter::SkOffsetImageFilter(SkReadBuffer& buffer)
-  : INHERITED(1, buffer) {
-    buffer.readPoint(&fOffset);
-    buffer.validate(SkScalarIsFinite(fOffset.fX) &&
-                    SkScalarIsFinite(fOffset.fY));
-}
-#endif