FileWrapper[Impl] modifications and actually remove the "Impl" class.

webrtc/system_wrappers/source/data_log.cc

Index: webrtc/system_wrappers/source/data_log.cc
diff --git a/webrtc/system_wrappers/source/data_log.cc b/webrtc/system_wrappers/source/data_log.cc
index 778769603bc745be138c90179939e47c76718e27..715023b3ea91f0b332c2394d1c54830565d1fb3b 100644
--- a/webrtc/system_wrappers/source/data_log.cc
+++ b/webrtc/system_wrappers/source/data_log.cc
@@ -205,7 +205,7 @@ int LogTable::InsertCell(const std::string& column_name,
 int LogTable::CreateLogFile(const std::string& file_name) {
   if (file_name.length() == 0)
     return -1;
-  if (file_->Open())
+  if (file_->is_open())
     return -1;
   file_->OpenFile(file_name.c_str(),
                   false,  // Open with read/write permissions