Disable --harmony-object-observe

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index e0d7f51a4f9f385485bc37f3ae7e8ae9d6397863..c31842ce3c6d474d12512d9dae0f3837c3e26430 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -204,6 +204,7 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
 
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS(V)                                                \
+  V(harmony_object_observe, "harmony Object.observe")                        \
   V(harmony_modules, "harmony modules")                                      \
   V(harmony_function_sent, "harmony function.sent")                          \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")                  \
@@ -226,7 +227,6 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
   V(harmony_default_parameters, "harmony default parameters")             \
   V(harmony_destructuring_assignment, "harmony destructuring assignment") \
   V(harmony_destructuring_bind, "harmony destructuring bind")             \
-  V(harmony_object_observe, "harmony Object.observe")                     \
   V(harmony_tostring, "harmony toString")                                 \
   V(harmony_regexps, "harmony regular expression extensions")             \
   V(harmony_unicode_regexps, "harmony unicode regexps")                   \