Revert 87415 - Convert more interfaces to the new thunk system. This goes up to and including

ppapi/shared_impl/tracker_base.h

 // 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.
 
 #ifndef PPAPI_SHARED_IMPL_TRACKER_BASE_H_
 #define PPAPI_SHARED_IMPL_TRACKER_BASE_H_
 
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/proxy/interface_id.h"
@@ skipping 22 matching lines @@
   static TrackerBase* Get();
 
   // Returns the resource object corresponding to the given ID, or NULL if
   // there isn't one.
   virtual ResourceObjectBase* GetResourceAPI(PP_Resource res) = 0;
 
   // Returns the function object corresponding to the given ID, or NULL if
   // there isn't one.
   virtual FunctionGroupBase* GetFunctionAPI(PP_Instance inst,
                                             pp::proxy::InterfaceID id) = 0;
-
-  // Returns the instance corresponding to the given resource, or 0 if the
-  // resource is invalid.
-  virtual PP_Instance GetInstanceForResource(PP_Resource resource) = 0;
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_TRACKER_BASE_H_