Do PPB_FileIO Query and Read in the plugin process.

ppapi/shared_impl/tracked_callback_unittest.cc

Index: ppapi/shared_impl/tracked_callback_unittest.cc
diff --git a/ppapi/shared_impl/tracked_callback_unittest.cc b/ppapi/shared_impl/tracked_callback_unittest.cc
index a9961f015b5ea5d70bad76c25679fbc6d61acd3d..68f0fb54fd0d439b0faa83957bfc4834aee16602 100644
--- a/ppapi/shared_impl/tracked_callback_unittest.cc
+++ b/ppapi/shared_impl/tracked_callback_unittest.cc
@@ -42,6 +42,7 @@ struct CallbackRunInfo {
   CallbackRunInfo() : run_count(0), result(1) {}
   unsigned run_count;
   int32_t result;
+  int32_t completion_task_result;
 };
 
 void TestCallback(void* user_data, int32_t result) {
@@ -51,6 +52,10 @@ void TestCallback(void* user_data, int32_t result) {
     info->result = result;
 }
 
+int32_t TestCompletionTask(int32_t result) {
+  return
+}
+
 }  // namespace
 
 // CallbackShutdownTest --------------------------------------------------------