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

chrome/browser/prerender/prerender_browsertest.cc

Index: chrome/browser/prerender/prerender_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 0c13cbc89e06597733d9145c23aeb97f0728ee48..10eae82a26ec94fbd84fd947d3d91f3414df25a5 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -27,6 +27,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/test/test_timeouts.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/browsing_data/browsing_data_helper.h"
@@ -3260,10 +3261,13 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, HttpPost) {
 // Manager API. The page should be killed.
 IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, AutosigninInPrerenderer) {
   // Set up a credential in the password store.
-  PasswordStoreFactory::GetInstance()->SetTestingFactory(
-      current_browser()->profile(),
-      password_manager::BuildPasswordStore<
-          content::BrowserContext, password_manager::TestPasswordStore>);
+  {
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    PasswordStoreFactory::GetInstance()->SetTestingFactory(
+        current_browser()->profile(),
+        password_manager::BuildPasswordStore<
+            content::BrowserContext, password_manager::TestPasswordStore>);
+  }
   scoped_refptr<password_manager::TestPasswordStore> password_store =
       static_cast<password_manager::TestPasswordStore*>(
           PasswordStoreFactory::GetForProfile(