Always run the second pass of the phantom callbacks synchronously if...

Always run the second pass of the phantom callbacks synchronously if --predictable or --optimize_for_size are set.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1245093004

Cr-Commit-Position: refs/heads/master@{#29771}

src/global-handles.cc

@@ -840,7 +840,7 @@ int GlobalHandles::DispatchPendingPhantomCallbacks(
     }
   }
   if (pending_phantom_callbacks_.length() > 0) {
-    if (synchronous_second_pass) {
+    if (FLAG_optimize_for_size || FLAG_predictable || synchronous_second_pass) {
       InvokeSecondPassPhantomCallbacks(&pending_phantom_callbacks_, isolate());
     } else {
       auto task = new PendingPhantomCallbacksSecondPassTask(