Relanding this with fixes to the mac dbg builder

webkit/plugins/ppapi/resource_helper.cc

Index: webkit/plugins/ppapi/resource_helper.cc
===================================================================
--- webkit/plugins/ppapi/resource_helper.cc	(revision 118405)
+++ webkit/plugins/ppapi/resource_helper.cc	(working copy)
@@ -17,9 +17,14 @@
 // static
 PluginInstance* ResourceHelper::GetPluginInstance(
     const ::ppapi::Resource* resource) {
-  return HostGlobals::Get()->GetInstance(resource->pp_instance());
+  return PPInstanceToPluginInstance(resource->pp_instance());
 }
 
+PluginInstance* ResourceHelper::PPInstanceToPluginInstance(
+    PP_Instance instance) {
+  return HostGlobals::Get()->GetInstance(instance);
+}
+
 PluginModule* ResourceHelper::GetPluginModule(
     const ::ppapi::Resource* resource) {
   PluginInstance* instance = GetPluginInstance(resource);