Migrate Extensions code to Task Scheduler API

chrome/browser/extensions/api/storage/policy_value_store.cc

Index: chrome/browser/extensions/api/storage/policy_value_store.cc
diff --git a/chrome/browser/extensions/api/storage/policy_value_store.cc b/chrome/browser/extensions/api/storage/policy_value_store.cc
index 02ceaafbb0d8504293a626c564da66bc10975f5a..05d4819522e6ceb5ffae310af6ec7d60d3f1b16f 100644
--- a/chrome/browser/extensions/api/storage/policy_value_store.cc
+++ b/chrome/browser/extensions/api/storage/policy_value_store.cc
@@ -10,12 +10,10 @@
 #include "base/values.h"
 #include "components/policy/core/common/policy_map.h"
 #include "components/policy/core/common/policy_types.h"
-#include "content/public/browser/browser_thread.h"
+#include "extensions/browser/api/storage/backend_task_runner.h"
 #include "extensions/browser/api/storage/settings_namespace.h"
 #include "extensions/browser/value_store/value_store_change.h"
 
-using content::BrowserThread;
-
 namespace extensions {
 
 namespace {
@@ -38,7 +36,7 @@ PolicyValueStore::PolicyValueStore(
 PolicyValueStore::~PolicyValueStore() {}
 
 void PolicyValueStore::SetCurrentPolicy(const policy::PolicyMap& policy) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+  DCHECK(IsOnBackendSequence());
   // Convert |policy| to a dictionary value. Only include mandatory policies
   // for now.
   base::DictionaryValue current_policy;