Add WriteIsolatedOutput() functions

webrtc/base/file_unittest.cc

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 171 matching lines @@
     ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
   }
 
   {
     Pathname path(path_);
     File file = File::Create(path);
     ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
   }
 }
 
+TEST_F(FileTest, ShouldBeAbleToRemoveFile) {
+  {
+    File file = File::Open(Pathname(path_));
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+
+  ASSERT_TRUE(File::Remove(Pathname(path_))) << "Error: " << LastError();
+}
+
 }  // namespace rtc