Pepper and WebKit API change to support a plugin knowing if a scrollbar is an overlay one.

ppapi/thunk/ppb_scrollbar_group_thunk.cc

+// Copyright (c) 2011 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/thunk/thunk.h"
+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_scrollbar_group_api.h"
+#include "ppapi/thunk/resource_creation_api.h"
+
+namespace ppapi {
+namespace thunk {
+
+typedef EnterResource<PPB_ScrollbarGroup_API> EnterScrollbarGroup;
+
+namespace {
+
+PP_Resource Create(PP_Instance instance) {
+  EnterFunction<ResourceCreationAPI> enter(instance, true);
+  if (enter.failed())
+    return 0;
+  return enter.functions()->CreateScrollbarGroup(instance);
+}
+
+const PPB_ScrollbarGroup_Dev g_ppb_scrollbar_group_thunk = {
+  &Create,
+};
+
+}  // namespace
+
+const PPB_ScrollbarGroup_Dev* GetPPB_ScrollbarGroup_Thunk() {
+  return &g_ppb_scrollbar_group_thunk;
+}
+
+}  // namespace thunk
+}  // namespace ppapi