Add ScopedPlatformFileCloser to base.

There are several places that need to be sure to close a platform file and have implemented a scoped to ensure that it is done.  Instead of adding yet another version of this code, this moves it into base and updates all known implementations to use it.

BUG=NONE

Review URL: https://chromiumcodereview.appspot.com/20154002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@213895 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 44 insertions, 0 deletions

diff --git a/base/base.gypi b/base/base.gypi
index 5085018..bd89f3e 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -192,6 +192,8 @@
           'files/memory_mapped_file.h',
           'files/memory_mapped_file_posix.cc',
           'files/memory_mapped_file_win.cc',
+          'files/scoped_platform_file_closer.cc',
+          'files/scoped_platform_file_closer.h',
           'files/scoped_temp_dir.cc',
           'files/scoped_temp_dir.h',
           'float_util.h',
diff --git a/base/files/scoped_platform_file_closer.cc b/base/files/scoped_platform_file_closer.cc
new file mode 100644
index 0000000..44f6752
--- /dev/null
+++ b/base/files/scoped_platform_file_closer.cc
@@ -0,0 +1,16 @@
+// Copyright 2013 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.
+
+#include "base/files/scoped_platform_file_closer.h"
+
+namespace base {
+namespace internal {
+
+void PlatformFileCloser::operator()(PlatformFile* file) const {
+  if (file && *file != kInvalidPlatformFileValue)
+    ClosePlatformFile(*file);
+}
+
+}  // namespace internal
+}  // namespace base
diff --git a/base/files/scoped_platform_file_closer.h b/base/files/scoped_platform_file_closer.h
new file mode 100644
index 0000000..8fe4a28
--- /dev/null
+++ b/base/files/scoped_platform_file_closer.h
@@ -0,0 +1,26 @@
+// Copyright 2013 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 BASE_FILES_SCOPED_PLATFORM_FILE_CLOSER_H_
+#define BASE_FILES_SCOPED_PLATFORM_FILE_CLOSER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/platform_file.h"
+
+namespace base {
+
+namespace internal {
+
+struct BASE_EXPORT PlatformFileCloser {
+  void operator()(PlatformFile* file) const;
+};
+
+}  // namespace internal
+
+typedef scoped_ptr<PlatformFile, internal::PlatformFileCloser>
+    ScopedPlatformFileCloser;
+
+}  // namespace base
+
+#endif  // BASE_FILES_SCOPED_PLATFORM_FILE_CLOSER_H_