Base: Don't check for thread restrictions when closing a file doesn't do IO.

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 199 matching lines @@
   return file_ >= 0;
 }
 
 PlatformFile File::TakePlatformFile() {
   PlatformFile file = file_;
   file_ = kInvalidPlatformFileValue;
   return file;
 }
 
 void File::Close() {
-  base::ThreadRestrictions::AssertIOAllowed();
   if (!IsValid())
     return;
 
+  base::ThreadRestrictions::AssertIOAllowed();
   if (!IGNORE_EINTR(close(file_)))
     file_ = kInvalidPlatformFileValue;
 }
 
 int64 File::Seek(Whence whence, int64 offset) {
   base::ThreadRestrictions::AssertIOAllowed();
   DCHECK(IsValid());
   if (file_ < 0 || offset < 0)
     return -1;
 
@@ skipping 237 matching lines @@
       return FILE_ERROR_FAILED;
   }
 }
 
 void File::SetPlatformFile(PlatformFile file) {
   DCHECK_EQ(file_, kInvalidPlatformFileValue);
   file_ = file;
 }
 
 }  // namespace base