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

chrome/browser/policy/policy_browsertest.cc

Index: chrome/browser/policy/policy_browsertest.cc
diff --git a/chrome/browser/policy/policy_browsertest.cc b/chrome/browser/policy/policy_browsertest.cc
index 021efe750aaa4860ad5a2228fd36f4e487290c9e..8fe1a46eb5a9123621cf7a4c969ec5965d034a3a 100644
--- a/chrome/browser/policy/policy_browsertest.cc
+++ b/chrome/browser/policy/policy_browsertest.cc
@@ -34,6 +34,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "base/test/test_file_util.h"
 #include "base/threading/sequenced_worker_pool.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ -875,6 +876,7 @@ IN_PROC_BROWSER_TEST_F(LocalePolicyTest, ApplicationLocaleValue) {
   EXPECT_EQ(french_title, title);
 
   // Make sure this is really French and differs from the English title.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   std::string loaded =
       ui::ResourceBundle::GetSharedInstance().ReloadLocaleResources("en-US");
   EXPECT_EQ("en-US", loaded);
@@ -1434,6 +1436,7 @@ IN_PROC_BROWSER_TEST_F(PolicyTest, DownloadDirectory) {
   // Verifies that the download directory can be forced by policy.
 
   // Set the initial download directory.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir initial_dir;
   ASSERT_TRUE(initial_dir.CreateUniqueTempDir());
   browser()->profile()->GetPrefs()->SetFilePath(
@@ -1832,6 +1835,7 @@ IN_PROC_BROWSER_TEST_F(PolicyTest, MAYBE_ExtensionInstallSources) {
       URLRequestMockHTTPJob::GetMockUrl("extensions/*"));
   const GURL referrer_url(URLRequestMockHTTPJob::GetMockUrl("policy/*"));
 
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir download_directory;
   ASSERT_TRUE(download_directory.CreateUniqueTempDir());
   DownloadPrefs* download_prefs =