Revert "Enable Object.observe by default"

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 2ff70f3c98be380e7e0a17f7466108f78fd4e8d0..61361f82f22f11ae58c564ee8f4ebe2f541443fa 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1577,12 +1577,6 @@ void Genesis::InstallNativeFunctions() {
   INSTALL_NATIVE(JSObject, "functionCache", function_cache);
   INSTALL_NATIVE(JSFunction, "ToCompletePropertyDescriptor",
                  to_complete_property_descriptor);
-  INSTALL_NATIVE(JSFunction, "NotifyChange", observers_notify_change);
-  INSTALL_NATIVE(JSFunction, "EnqueueSpliceRecord", observers_enqueue_splice);
-  INSTALL_NATIVE(JSFunction, "BeginPerformSplice",
-                 observers_begin_perform_splice);
-  INSTALL_NATIVE(JSFunction, "EndPerformSplice",
-                 observers_end_perform_splice);
 }
 
 
@@ -1597,6 +1591,14 @@ void Genesis::InstallExperimentalNativeFunctions() {
     INSTALL_NATIVE(JSFunction, "DerivedSetTrap", derived_set_trap);
     INSTALL_NATIVE(JSFunction, "ProxyEnumerate", proxy_enumerate);
   }
+  if (FLAG_harmony_observation) {
+    INSTALL_NATIVE(JSFunction, "NotifyChange", observers_notify_change);
+    INSTALL_NATIVE(JSFunction, "EnqueueSpliceRecord", observers_enqueue_splice);
+    INSTALL_NATIVE(JSFunction, "BeginPerformSplice",
+                   observers_begin_perform_splice);
+    INSTALL_NATIVE(JSFunction, "EndPerformSplice",
+                   observers_end_perform_splice);
+  }
 }
 
 #undef INSTALL_NATIVE
@@ -2040,6 +2042,7 @@ bool Genesis::InstallExperimentalNatives() {
     INSTALL_EXPERIMENTAL_NATIVE(i, symbols, "symbol.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, proxies, "proxy.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, collections, "collection.js")
+    INSTALL_EXPERIMENTAL_NATIVE(i, observation, "object-observe.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, promises, "promise.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, generators, "generator.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, iteration, "array-iterator.js")