Added Net logging to FileStream.

net/base/file_stream_metrics.h

Index: net/base/file_stream_metrics.h
diff --git a/net/base/file_stream_metrics.h b/net/base/file_stream_metrics.h
index cdf16e5b01a6d8af980057dac975a2fb92478567..5adb7e23141f58627879443af8ef2577e8bd76de 100644
--- a/net/base/file_stream_metrics.h
+++ b/net/base/file_stream_metrics.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -36,6 +36,9 @@ int MaxFileErrorUmaValue();
 // |record| is a flag indicating that we are interested in this error.
 void RecordFileError(int error, FileErrorSource source, bool record);
 
+// Gets a description for the source of a file error.
+const char* GetFileErrorSourceName(FileErrorSource source);
+
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_METRICS_H_