Update Linux to use scoped_refptr<T>::get() rather than implicit "operator T*"

ppapi/proxy/file_ref_resource.cc

 // Copyright 2013 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/proxy/file_ref_resource.h"
 
 #include "ppapi/c/pp_directory_entry.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/proxy/ppapi_messages.h"
@@ skipping 193 matching lines @@
 // TODO(teravest): Remove this when we are finished moving to the new proxy.
 int32_t FileRefResource::ReadDirectoryEntriesInHost(
     linked_ptr<std::vector<ppapi::PPB_FileRef_CreateInfo> > files,
     linked_ptr<std::vector<PP_FileType> > file_types,
     scoped_refptr<TrackedCallback> callback) {
   NOTREACHED();
   return PP_ERROR_FAILED;
 }
 
 PP_Var FileRefResource::GetAbsolutePath() {
-  if (!absolute_path_var_) {
+  if (!absolute_path_var_.get()) {
     std::string absolute_path;
     int32_t result = SyncCall<PpapiPluginMsg_FileRef_GetAbsolutePathReply>(
         BROWSER, PpapiHostMsg_FileRef_GetAbsolutePath(), &absolute_path);
     if (result != PP_OK)
       return PP_MakeUndefined();
     absolute_path_var_ = new StringVar(absolute_path);
   }
   return absolute_path_var_->GetPPVar();
 }
 
@@ skipping 43 matching lines @@
       entries.push_back(entry);
     }
 
     writer.StoreVector(entries);
   }
   callback->Run(params.result());
 }
 
 }  // namespace proxy
 }  // namespace ppapi