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

ppapi/thunk/ppb_scrollbar_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_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
 namespace ppapi {
@@ skipping 15 matching lines @@
   return PP_FromBool(enter.succeeded());
 }
 
 uint32_t GetThickness(PP_Resource scrollbar) {
   EnterScrollbar enter(scrollbar, true);
   if (enter.failed())
     return 0;
   return enter.object()->GetThickness();
 }
 
+PP_Bool IsOverlay(PP_Resource scrollbar) {
+  EnterScrollbar enter(scrollbar, true);
+  if (enter.failed())
+    return PP_FALSE;
+  return PP_FromBool(enter.object()->IsOverlay());
+}
+
 uint32_t GetValue(PP_Resource scrollbar) {
   EnterScrollbar enter(scrollbar, true);
   if (enter.failed())
     return 0;
   return enter.object()->GetValue();
 }
 
 void SetValue(PP_Resource scrollbar, uint32_t value) {
   EnterScrollbar enter(scrollbar, true);
   if (enter.succeeded())
@@ skipping 13 matching lines @@
   if (enter.succeeded())
     enter.object()->SetTickMarks(tick_marks, count);
 }
 
 void ScrollBy(PP_Resource scrollbar, PP_ScrollBy_Dev unit, int32_t multiplier) {
   EnterScrollbar enter(scrollbar, true);
   if (enter.succeeded())
     enter.object()->ScrollBy(unit, multiplier);
 }
 
-const PPB_Scrollbar_0_4_Dev g_ppb_scrollbar_thunk = {
+const PPB_Scrollbar_0_5_Dev g_ppb_scrollbar_thunk = {
   &Create,
   &IsScrollbar,
   &GetThickness,
+  &IsOverlay,
   &GetValue,
   &SetValue,
   &SetDocumentSize,
   &SetTickMarks,
   &ScrollBy
 };
 
 }  // namespace
 
-const PPB_Scrollbar_0_4_Dev* GetPPB_Scrollbar_Thunk() {
+const PPB_Scrollbar_0_5_Dev* GetPPB_Scrollbar_Thunk() {
   return &g_ppb_scrollbar_thunk;
 }
 
 }  // namespace thunk
 }  // namespace ppapi