Record UMA statistics for file_stream operations.

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
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index 0000000000000000000000000000000000000000..cdf16e5b01a6d8af980057dac975a2fb92478567
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+++ b/net/base/file_stream_metrics.h
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+// 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.
+
+// File error statistics gathering.
+
+#ifndef NET_BASE_FILE_STREAM_METRICS_H_
+#define NET_BASE_FILE_STREAM_METRICS_H_
+#pragma once
+
+namespace net {
+
+enum FileErrorSource {
+  FILE_ERROR_SOURCE_OPEN = 0,
+  FILE_ERROR_SOURCE_WRITE,
+  FILE_ERROR_SOURCE_READ,
+  FILE_ERROR_SOURCE_SEEK,
+  FILE_ERROR_SOURCE_FLUSH,
+  FILE_ERROR_SOURCE_SET_EOF,
+  FILE_ERROR_SOURCE_GET_SIZE,
+  FILE_ERROR_SOURCE_COUNT,
+};
+
+// UMA error statistics gathering.
+// Put the error value into a bucket.
+int GetFileErrorUmaBucket(int error);
+
+// The largest bucket number, plus 1.
+int MaxFileErrorUmaBucket();
+
+// The highest error value we want to individually report.
+int MaxFileErrorUmaValue();
+
+// |error| is a platform-specific error (Windows or Posix).
+// |source| indicates the operation that resulted in the error.
+// |record| is a flag indicating that we are interested in this error.
+void RecordFileError(int error, FileErrorSource source, bool record);
+
+}  // namespace net
+
+#endif  // NET_BASE_FILE_STREAM_METRICS_H_