Add the PP_Instance to resource object base.

ppapi/shared_impl/resource_object_base.h

Index: ppapi/shared_impl/resource_object_base.h
diff --git a/ppapi/shared_impl/resource_object_base.h b/ppapi/shared_impl/resource_object_base.h
index 8f5da77ebd644ec320128e60dacc12eb53e88bc2..34085255a4e52ecc1ab5f4da2e2e66f0f1d33aac 100644
--- a/ppapi/shared_impl/resource_object_base.h
+++ b/ppapi/shared_impl/resource_object_base.h
@@ -8,6 +8,7 @@
 #include <stddef.h>  // For NULL.
 
 #include "base/memory/ref_counted.h"
+#include "ppapi/c/pp_instance.h"
 
 #define FOR_ALL_PPAPI_RESOURCE_APIS(F) \
   F(PPB_AudioConfig_API) \
@@ -55,8 +56,11 @@ FOR_ALL_PPAPI_RESOURCE_APIS(DECLARE_RESOURCE_CLASS)
 
 class ResourceObjectBase : public base::RefCounted<ResourceObjectBase> {
  public:
+  ResourceObjectBase(PP_Instance instance);
   virtual ~ResourceObjectBase();
 
+  PP_Instance pp_instance() const { return pp_instance_; }
+
   // Dynamic casting for this object. Returns the pointer to the given type if
   // Inheritance-based dynamic casting for this object. Returns the pointer to
   // the given type if it's supported. Derived classes override the functions
@@ -68,6 +72,11 @@ class ResourceObjectBase : public base::RefCounted<ResourceObjectBase> {
 
   // Template-based dynamic casting. See specializations below.
   template <typename T> T* GetAs() { return NULL; }
+
+ private:
+  PP_Instance pp_instance_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ResourceObjectBase);
 };
 
 // Template-based dynamic casting. These specializations forward to the