Fix integration tests in src/chrome and src/extensions so that we can turn on IO thread checks wi...

chrome/test/remoting/qunit_browser_test_runner.cc

 // Copyright 2014 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 "chrome/test/remoting/qunit_browser_test_runner.h"
 
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/values.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/test/browser_test_utils.h"
 #include "net/base/filename_util.h"
 
 void QUnitBrowserTestRunner::QUnitStart(content::WebContents* web_contents) {
   std::string result;
 
@@ skipping 13 matching lines @@
   // Extract the fields.
   bool passed;
   ASSERT_TRUE(dict_value->GetBoolean("passed", &passed));
   std::string error_message;
   ASSERT_TRUE(dict_value->GetString("errorMessage", &error_message));
 
   EXPECT_TRUE(passed) << error_message;
 }
 
 void QUnitBrowserTestRunner::RunTest(const base::FilePath& file) {
-  ASSERT_TRUE(PathExists(file)) << "Error: The QUnit test suite <"
-                                << file.value() << "> does not exist.";
+  {
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    ASSERT_TRUE(PathExists(file)) << "Error: The QUnit test suite <"
+                                  << file.value() << "> does not exist.";
+  }
   ui_test_utils::NavigateToURL(browser(), net::FilePathToFileURL(file));
 
   content::WebContents* web_contents =
       browser()->tab_strip_model()->GetActiveWebContents();
   ASSERT_TRUE(web_contents);
 
   std::string result;
   QUnitStart(web_contents);
 }