Revert of Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.

src/effects/SkAvoidXfermode.cpp

Index: src/effects/SkAvoidXfermode.cpp
diff --git a/src/effects/SkAvoidXfermode.cpp b/src/effects/SkAvoidXfermode.cpp
index 41c4e9646df4078ae0139ee2d559b6f9f68d1b67..b596bfdb7309f439b0024833f72b437b1fef5ccd 100644
--- a/src/effects/SkAvoidXfermode.cpp
+++ b/src/effects/SkAvoidXfermode.cpp
@@ -20,6 +20,14 @@
     fDistMul = (256 << 14) / (tolerance + 1);
     fMode = mode;
 }
+
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+SkAvoidXfermode::SkAvoidXfermode(SkReadBuffer& buffer) : INHERITED(buffer) {
+    fOpColor = buffer.readColor();
+    fDistMul = buffer.readUInt();
+    fMode = (Mode)buffer.readUInt();
+}
+#endif
 
 SkFlattenable* SkAvoidXfermode::CreateProc(SkReadBuffer& buffer) {
     const SkColor color = buffer.readColor();