Make MediaFileUtil run on thread pool.

webkit/fileapi/file_system_url_request_job_unittest.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 "webkit/fileapi/file_system_url_request_job.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/file_path.h"
@@ skipping 56 matching lines @@
   virtual void SetUp() OVERRIDE {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
 
     special_storage_policy_ = new quota::MockSpecialStoragePolicy;
     // We use the main thread so that we can get the root path synchronously.
     // TODO(adamk): Run this on the FILE thread we've created as well.
     file_system_context_ =
         new FileSystemContext(
             base::MessageLoopProxy::current(),
             base::MessageLoopProxy::current(),
+            base::MessageLoopProxy::current(),
             special_storage_policy_, NULL,
             temp_dir_.path(),
             CreateDisallowFileAccessOptions());
 
     file_system_context_->sandbox_provider()->ValidateFileSystemRoot(
         GURL("http://remote/"), kFileSystemTypeTemporary, true,  // create
         base::Bind(&FileSystemURLRequestJobTest::OnValidateFileSystem,
                    weak_factory_.GetWeakPtr()));
     MessageLoop::current()->RunAllPending();
 
@@ skipping 279 matching lines @@
 
   TestRequest(CreateFileSystemURL(kFilename));
 
   std::string mime_type_from_job;
   request_->GetMimeType(&mime_type_from_job);
   EXPECT_EQ(mime_type_direct, mime_type_from_job);
 }
 
 }  // namespace
 }  // namespace fileapi