Add new permission string for extensions that override new tab pages.

extensions/common/permissions/extensions_api_permissions.cc

Index: extensions/common/permissions/extensions_api_permissions.cc
diff --git a/extensions/common/permissions/extensions_api_permissions.cc b/extensions/common/permissions/extensions_api_permissions.cc
index e9eba1986fb51c3171f8858fc6b047e77e29edb7..05910ffff36008f6d07fdd169dd81332fa0324c0 100644
--- a/extensions/common/permissions/extensions_api_permissions.cc
+++ b/extensions/common/permissions/extensions_api_permissions.cc
@@ -31,7 +31,7 @@ std::vector<std::unique_ptr<APIPermissionInfo>>
 ExtensionsAPIPermissions::GetAllPermissions() const {
   // WARNING: If you are modifying a permission message in this list, be sure to
   // add the corresponding permission message rule to
-  // ChromePermissionMessageProvider::GetPermissionMessages as well.
+  // ChromePermissionMessageRule::GetAllRules as well.
   APIPermissionInfo::InitInfo permissions_to_register[] = {
       {APIPermission::kAlarms, "alarms"},
       {APIPermission::kAlphaEnabled, "app.window.alpha"},
@@ -71,6 +71,8 @@ ExtensionsAPIPermissions::GetAllPermissions() const {
       {APIPermission::kNetworkingOnc, "networking.onc"},
       {APIPermission::kNetworkingPrivate, "networkingPrivate",
        APIPermissionInfo::kFlagCannotBeOptional},
+      {APIPermission::kNewTabPageOverride, "newTabPageOverride",
+       APIPermissionInfo::kFlagCannotBeOptional},
       {APIPermission::kPower, "power"},
       {APIPermission::kPrinterProvider, "printerProvider"},
       {APIPermission::kSerial, "serial"},