Added WARN_UNUSED_RESULT to ScopedTempDir methods.

chrome/browser/process_singleton_linux.cc

 // 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.
 
 // On Linux, when the user tries to launch a second copy of chrome, we check
 // for a socket in the user's profile directory.  If the socket file is open we
 // send a message to the first chrome browser process with the current
 // directory and second process command line flags.  The second process then
 // exits.
 //
@@ skipping 933 matching lines @@
   FilePath remote_cookie_path =
       socket_dir_.path().Append(chrome::kSingletonCookieFilename);
   UnlinkPath(socket_path_);
   UnlinkPath(cookie_path_);
   if (!SymlinkPath(socket_target_path, socket_path_) ||
       !SymlinkPath(cookie, cookie_path_) ||
       !SymlinkPath(cookie, remote_cookie_path)) {
     // We've already locked things, so we can't have lost the startup race,
     // but something doesn't like us.
     LOG(ERROR) << "Failed to create symlinks.";
-    socket_dir_.Delete();
+    if (!socket_dir_.Delete())
+      LOG(ERROR) << "Encountered a problem when deleting socket directory.";
     return false;
   }
 
   SetupSocket(socket_target_path.value(), &sock, &addr);
 
   if (bind(sock, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) < 0) {
     PLOG(ERROR) << "Failed to bind() " << socket_target_path.value();
     CloseSocket(sock);
     return false;
   }
@@ skipping 12 matching lines @@
     sock));
 
   return true;
 }
 
 void ProcessSingleton::Cleanup() {
   UnlinkPath(socket_path_);
   UnlinkPath(cookie_path_);
   UnlinkPath(lock_path_);
 }