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

ppapi/cpp/dev/widget_client_dev.cc

 // Copyright (c) 2010 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/dev/widget_client_dev.h"
 
 #include "ppapi/c/dev/ppp_scrollbar_dev.h"
 #include "ppapi/c/dev/ppp_widget_dev.h"
 #include "ppapi/cpp/dev/scrollbar_dev.h"
 #include "ppapi/cpp/dev/widget_dev.h"
@@ skipping 33 matching lines @@
                             PP_Resource scrollbar_id,
                             uint32_t value) {
   void* object =
       pp::Instance::GetPerInstanceObject(instance, kPPPScrollbarInterface);
   if (!object)
     return;
   return static_cast<WidgetClient_Dev*>(object)->ScrollbarValueChanged(
       Scrollbar_Dev(scrollbar_id), value);
 }
 
+void Scrollbar_OverlayChanged(PP_Instance instance,
+                              PP_Resource scrollbar_id,
+                              PP_Bool overlay) {
+  void* object =
+      pp::Instance::GetPerInstanceObject(instance, kPPPScrollbarInterface);
+  if (!object)
+    return;
+  return static_cast<WidgetClient_Dev*>(object)->ScrollbarOverlayChanged(
+      Scrollbar_Dev(scrollbar_id), PP_ToBool(overlay));
+}
+
 static PPP_Scrollbar_Dev scrollbar_interface = {
   &Scrollbar_ValueChanged,
+  &Scrollbar_OverlayChanged,
 };
 
 }  // namespace
 
 WidgetClient_Dev::WidgetClient_Dev(Instance* instance)
     : associated_instance_(instance) {
   pp::Module::Get()->AddPluginInterface(kPPPWidgetInterface, &widget_interface);
   associated_instance_->AddPerInstanceObject(kPPPWidgetInterface, this);
   pp::Module::Get()->AddPluginInterface(kPPPScrollbarInterface,
                                         &scrollbar_interface);
   associated_instance_->AddPerInstanceObject(kPPPScrollbarInterface, this);
 }
 
 WidgetClient_Dev::~WidgetClient_Dev() {
   associated_instance_->RemovePerInstanceObject(kPPPScrollbarInterface, this);
   associated_instance_->RemovePerInstanceObject(kPPPWidgetInterface, this);
 }
 
 }  // namespace pp