Keep event page alive when there's some Pepper plugin on it.

ppapi/tests/extensions/load_unload/load_unload.cc

Index: ppapi/tests/extensions/load_unload/load_unload.cc
diff --git a/ppapi/tests/extensions/load_unload/load_unload.cc b/ppapi/tests/extensions/load_unload/load_unload.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f16abbc24a0ca1edcb22228523b7bbeac8dda46b
--- /dev/null
+++ b/ppapi/tests/extensions/load_unload/load_unload.cc
@@ -0,0 +1,25 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/module.h"
+
+namespace {
+
+class Module : public pp::Module {
+ public:
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new pp::Instance(instance);
+  }
+};
+
+}  // namespace
+
+namespace pp {
+
+Module* CreateModule() {
+  return new ::Module();
+}
+
+}  // namespace pp