More aggressive IO asserts in content_browsertests.

content/browser/cross_site_transfer_browsertest.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 <memory>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 423 matching lines @@
 IN_PROC_BROWSER_TEST_F(CrossSiteTransferTest, PostWithFileData) {
   // Navigate to the page with form that posts via 307 redirection to
   // |redirect_target_url| (cross-site from |form_url|).  Using 307 (rather than
   // 302) redirection is important to preserve the HTTP method and POST body.
   GURL form_url(embedded_test_server()->GetURL(
       "a.com", "/form_that_posts_cross_site.html"));
   GURL redirect_target_url(embedded_test_server()->GetURL("x.com", "/echoall"));
   EXPECT_TRUE(NavigateToURL(shell(), form_url));
 
   // Prepare a file to upload.
+  base::ThreadRestrictions::ScopedAllowIO allow_io_for_temp_dir;
   base::ScopedTempDir temp_dir;
   base::FilePath file_path;
   std::string file_content("test-file-content");
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   ASSERT_TRUE(base::CreateTemporaryFileInDir(temp_dir.path(), &file_path));
   ASSERT_LT(
       0, base::WriteFile(file_path, file_content.data(), file_content.size()));
 
   // Fill out the form to refer to the test file.
   std::unique_ptr<FileChooserDelegate> delegate(
@@ skipping 34 matching lines @@
       "document.getElementsByTagName('pre')[0].innerText);",
       &actual_page_body));
   EXPECT_THAT(actual_page_body, ::testing::HasSubstr(file_content));
   EXPECT_THAT(actual_page_body,
               ::testing::HasSubstr(file_path.BaseName().AsUTF8Unsafe()));
   EXPECT_THAT(actual_page_body,
               ::testing::HasSubstr("form-data; name=\"file\""));
 }
 
 }  // namespace content