[Chromecast] Use ScopedTemp[File|Dir] in tests.

chromecast/base/scoped_temp_file.h

+// Copyright 2015 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 CHROMECAST_BASE_SCOPED_TEMP_FILE_H_
+#define CHROMECAST_BASE_SCOPED_TEMP_FILE_H_
+
+#include <string>
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+
+namespace chromecast {
+
+// Creates a temporary file that is deleted when this object is destroyed,
+// unless the underlying file has been moved or deleted.
+// Warning: This class uses CHECKs, and should only be used for testing.
+class ScopedTempFile {
+ public:
+  ScopedTempFile();
+  ~ScopedTempFile();
+
+  // Return the path to the temporary file. Note that if the underlying file has
+  // been moved or deleted, this will still return the original path.
+  base::FilePath path() const { return path_; }
+
+  // Returns true if the underlying file exists, false otherwise. This will
+  // return false, for example, if the file has been moved or deleted.
+  bool FileExists() const;
+
+  // Write the contents of |str| to the file. Return the number of characters
+  // written, or -1 on error. CHECKs that FileExists() returns true.
+  int Write(const std::string& str);
+
+  // Read the file and return the contents. CHECKs that FileExists() returns
+  // true.
+  std::string Read() const;
+
+ private:
+  base::FilePath path_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedTempFile);
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_BASE_SCOPED_TEMP_FILE_H_