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

chrome/browser/ui/webui/policy_ui_browsertest.cc

Index: chrome/browser/ui/webui/policy_ui_browsertest.cc
diff --git a/chrome/browser/ui/webui/policy_ui_browsertest.cc b/chrome/browser/ui/webui/policy_ui_browsertest.cc
index c6ed1f25e2b1dbf708cf3c12a65e62bd47d75b1d..5514daf8734f8d483fb2c10300b33a5fb477423b 100644
--- a/chrome/browser/ui/webui/policy_ui_browsertest.cc
+++ b/chrome/browser/ui/webui/policy_ui_browsertest.cc
@@ -14,6 +14,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/test_extension_system.h"
@@ -280,6 +281,7 @@ IN_PROC_BROWSER_TEST_F(PolicyUITest, SendPolicyValues) {
 
 IN_PROC_BROWSER_TEST_F(PolicyUITest, ExtensionLoadAndSendPolicy) {
   ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIPolicyURL));
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir_;
   ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());