Pass --harmony-object-observe in tests that depend on it

test/cctest/test-microtask-delivery.cc

Index: test/cctest/test-microtask-delivery.cc
diff --git a/test/cctest/test-microtask-delivery.cc b/test/cctest/test-microtask-delivery.cc
index cc12c33f8e9e266323a67034198bbc83d1296d4d..f1f221abb2896305a4b565ba746539da04617545 100644
--- a/test/cctest/test-microtask-delivery.cc
+++ b/test/cctest/test-microtask-delivery.cc
@@ -58,6 +58,7 @@ class HarmonyIsolate {
 
 
 TEST(MicrotaskDeliverySimple) {
+  i::FLAG_harmony_object_observe = true;
   HarmonyIsolate isolate;
   v8::HandleScope scope(isolate.GetIsolate());
   LocalContext context(isolate.GetIsolate());
@@ -103,6 +104,7 @@ TEST(MicrotaskDeliverySimple) {
 
 
 TEST(MicrotaskPerIsolateState) {
+  i::FLAG_harmony_object_observe = true;
   HarmonyIsolate isolate;
   v8::HandleScope scope(isolate.GetIsolate());
   LocalContext context1(isolate.GetIsolate());