FBTF: Remove unneeded headers from base/ (part 10)

chrome/browser/chromeos/external_metrics.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
 #define CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
 #pragma once
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/hash_tables.h"
-#include "base/task.h"
+#include "base/ref_counted.h"
 
 namespace chromeos {
 
 // ExternalMetrics is a service that Chrome offers to Chrome OS to upload
 // metrics to the UMA server on its behalf.  Chrome periodically reads the
 // content of a well-know file, and parses it into name-value pairs, each
 // representing a Chrome OS metrics event. The events are logged using the
 // normal UMA mechanism. The file is then truncated to zero size. Chrome uses
 // flock() to synchronize accesses to the file.
 class ExternalMetrics : public base::RefCountedThreadSafe<ExternalMetrics> {
@@ skipping 55 matching lines @@
 
   // Used for testing only.
   RecorderType test_recorder_;
   FilePath test_path_;
   DISALLOW_COPY_AND_ASSIGN(ExternalMetrics);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_