Revert of Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.

src/effects/SkMatrixImageFilter.cpp

Index: src/effects/SkMatrixImageFilter.cpp
diff --git a/src/effects/SkMatrixImageFilter.cpp b/src/effects/SkMatrixImageFilter.cpp
index 919dff3994f3d822443c5601f47ed2a8dd6cd41f..8b07dd4a467833ba290dc97474fb1f9b799c4b45 100644
--- a/src/effects/SkMatrixImageFilter.cpp
+++ b/src/effects/SkMatrixImageFilter.cpp
@@ -30,6 +30,14 @@
                                                  uint32_t uniqueID) {
     return SkNEW_ARGS(SkMatrixImageFilter, (transform, filterLevel, input, uniqueID));
 }
+
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+SkMatrixImageFilter::SkMatrixImageFilter(SkReadBuffer& buffer)
+  : INHERITED(1, buffer) {
+    buffer.readMatrix(&fTransform);
+    fFilterLevel = static_cast<SkPaint::FilterLevel>(buffer.readInt());
+}
+#endif
 
 SkFlattenable* SkMatrixImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);