Fix cluster-fuzz found regression in d8 Workers.

Dumb typo introduced in refs/heads/master@{#29306}. I thought I was turning on
report_exceptions in Shell::ExecuteString, but instead I turned on print_result
(which assumes an interactive debugger and a HandleScope for the
utility_context_).

BUG=chromium:504727,chromium:504728
R=mstarzinger@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/1219563002

Cr-Commit-Position: refs/heads/master@{#29350}

src/d8.cc

@@ -1706,7 +1706,7 @@ void Worker::ExecuteInThread() {
         // First run the script
         Handle<String> file_name = String::NewFromUtf8(isolate, "unnamed");
         Handle<String> source = String::NewFromUtf8(isolate, script_);
-        if (Shell::ExecuteString(isolate, source, file_name, true, true)) {
+        if (Shell::ExecuteString(isolate, source, file_name, false, true)) {
           // Get the message handler
           Handle<Value> onmessage =
               global->Get(String::NewFromUtf8(isolate, "onmessage"));

test/mjsunit/regress/regress-crbug-504727.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --no-test
+
+if (this.Worker) {
+  function __f_4() {}
+  var __v_2 = new Worker(__f_4);
+}