Add LwwRegister CRDT

blimp/common/proto/helium.proto

Index: blimp/common/proto/helium.proto
diff --git a/blimp/common/proto/helium.proto b/blimp/common/proto/helium.proto
index 0b215f4f222de6d76350f1a268b8f2cd68f9a144..6d41238713463a390d681acaf69d525ad1576ea6 100644
--- a/blimp/common/proto/helium.proto
+++ b/blimp/common/proto/helium.proto
@@ -25,12 +25,20 @@ message TestChangesetMessage {
   int32 value2 = 2;
 }
 
+message LwwRegisterChangesetMessage {
+  oneof register {
+    int32 integer_value = 1;

[scf, 2016/10/10 19:45:46]

rename to something that convey the size: |i32_value|

[steimel, 2016/10/11 16:39:16]

Gotcha. If we end up keeping with protos instead of moving to CodedInputStreams,
I'll update the name

+    string string_value = 2;
+  }
+}
+
 // A union of serializable Changeset types. There will be one for each Helium
 // Object that requires serialization.
 message ChangesetMessage {
   oneof payload {
     // Sample message for the test
     TestChangesetMessage test = 1;
+    LwwRegisterChangesetMessage lww_register = 2;
   };
 }