date recent version bump for path serialization

Bug: skia:
Change-Id: I7f8fd114c3167e7787f80a9f800e5cff5b63c60a
Reviewed-on: https://skia-review.googlesource.com/110803
Reviewed-by: Mike Reed <reed@google.com>

src/core/SkPath_serial.cpp

@@ -26,7 +26,7 @@ enum SerializationVersions {
     // kPathPrivFirstDirection_Version = 1,
     kPathPrivLastMoveToIndex_Version = 2,
     kPathPrivTypeEnumVersion = 3,
-    kJustPublicData_Version = 4,
+    kJustPublicData_Version = 4,    // introduced Feb/2018
 
     kCurrent_Version = kJustPublicData_Version
 };