Support "always allow" for runtime script execution

extensions/browser/extension_prefs.cc

Index: extensions/browser/extension_prefs.cc
diff --git a/extensions/browser/extension_prefs.cc b/extensions/browser/extension_prefs.cc
index efe3ba419ecf4e82d62b4b8ff5ac80204abbf91b..b83d22316295956b8de9e2a7adb54840a3f9e611 100644
--- a/extensions/browser/extension_prefs.cc
+++ b/extensions/browser/extension_prefs.cc
@@ -142,6 +142,7 @@ const char kPrefUserDraggedApp[] = "user_dragged_app_ntp";
 // permissions because they may differ from those defined in the manifest.
 const char kPrefActivePermissions[] = "active_permissions";
 const char kPrefGrantedPermissions[] = "granted_permissions";
+const char kPrefPersistedPermissions[] = "persisted_permissions";
 
 // The preference names for PermissionSet values.
 const char kPrefAPIs[] = "api";
@@ -1133,6 +1134,28 @@ void ExtensionPrefs::SetActivePermissions(
       extension_id, kPrefActivePermissions, permissions);
 }
 
+PermissionSet* ExtensionPrefs::GetPersistedPermissions(
+    const std::string& extension_id) {
+  CHECK(Extension::IdIsValid(extension_id));
+  return ReadPrefAsPermissionSet(extension_id, kPrefPersistedPermissions);
+}
+
+void ExtensionPrefs::AddPersistedPermission(const std::string& extension_id,
+                                            const PermissionSet* permissions) {
+  scoped_refptr<PermissionSet> old_permissions(
+      GetPersistedPermissions(extension_id));
+  SetExtensionPrefPermissionSet(
+      extension_id,
+      kPrefPersistedPermissions,
+      PermissionSet::CreateUnion(old_permissions.get(), permissions));
+}
+
+void ExtensionPrefs::ClearPersistedPermissions(
+    const std::string& extension_id) {
+  SetExtensionPrefPermissionSet(
+      extension_id, kPrefPersistedPermissions, new PermissionSet());
+}
+
 void ExtensionPrefs::SetExtensionRunning(const std::string& extension_id,
     bool is_running) {
   base::Value* value = new base::FundamentalValue(is_running);