Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/policy/managed_mode_policy_provider.cc

Index: chrome/browser/policy/managed_mode_policy_provider.cc
diff --git a/chrome/browser/policy/managed_mode_policy_provider.cc b/chrome/browser/policy/managed_mode_policy_provider.cc
index 4b09f851af5228a09cade7d409f1345410ae16b6..149c03e0202b67f3306418e8f39d3bc303b7616f 100644
--- a/chrome/browser/policy/managed_mode_policy_provider.cc
+++ b/chrome/browser/policy/managed_mode_policy_provider.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/policy/managed_mode_policy_provider.h"
 
+#include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/policy/policy_bundle.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/json_pref_store.h"
@@ -20,11 +21,9 @@ const char ManagedModePolicyProvider::kPolicies[] = "policies";
 
 // static
 ManagedModePolicyProvider* ManagedModePolicyProvider::Create(Profile* profile) {
+  FilePath path = profile->GetPath().Append(chrome::kManagedModePolicyFilename);
   JsonPrefStore* pref_store =
-      new JsonPrefStore(profile->GetPath().Append(
-                            chrome::kManagedModePolicyFilename),
-                        BrowserThread::GetMessageLoopProxyForThread(
-                            BrowserThread::FILE));
+      JsonPrefStore::Create(path, BrowserThread::GetBlockingPool());
   return new ManagedModePolicyProvider(pref_store);
 }