[base] POSIX File::Unlock() didn't actually unlock file.

base/files/file_posix.cc

 // Copyright (c) 2012 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/file.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ skipping 52 matching lines @@
   ts_times[1].tv_nsec = times[1].tv_usec * 1000;
 
   return futimens(file, ts_times);
 #else
   return futimes(file, times);
 #endif
 }
 
 File::Error CallFcntlFlock(PlatformFile file, bool do_lock) {
   struct flock lock;
-  lock.l_type = F_WRLCK;
+  lock.l_type = do_lock ? F_WRLCK : F_UNLCK;
   lock.l_whence = SEEK_SET;
   lock.l_start = 0;
   lock.l_len = 0;  // Lock entire file.
-  if (HANDLE_EINTR(fcntl(file, do_lock ? F_SETLK : F_UNLCK, &lock)) == -1)
+  if (HANDLE_EINTR(fcntl(file, F_SETLK, &lock)) == -1)
     return File::OSErrorToFileError(errno);
   return File::FILE_OK;
 }
 #else  // defined(OS_NACL)
 
 bool IsOpenAppend(PlatformFile file) {
   // NaCl doesn't implement fcntl. Since NaCl's write conforms to the POSIX
   // standard and always appends if the file is opened with O_APPEND, just
   // return false here.
   return false;
@@ skipping 434 matching lines @@
   return !HANDLE_EINTR(fsync(file_.get()));
 #endif
 }
 
 void File::SetPlatformFile(PlatformFile file) {
   DCHECK(!file_.is_valid());
   file_.reset(file);
 }
 
 }  // namespace base