diff --git a/tools/under-control/src/RELEASE b/tools/under-control/src/RELEASE
index 01e87a5b..055876fd 100644
--- a/tools/under-control/src/RELEASE
+++ b/tools/under-control/src/RELEASE
@@ -1 +1 @@
-133.0.6943.60
+133.0.6943.99
diff --git a/tools/under-control/src/android_webview/browser/aw_field_trials.cc b/tools/under-control/src/android_webview/browser/aw_field_trials.cc
index 1ca5b374..0ce806e8 100755
--- a/tools/under-control/src/android_webview/browser/aw_field_trials.cc
+++ b/tools/under-control/src/android_webview/browser/aw_field_trials.cc
@@ -31,6 +31,12 @@
 
 namespace internal {
 
+// Duplicated from content/browser/file_system_access/features.cc to allow
+// WebView-only override.
+BASE_FEATURE(kFileSystemAccessDirectoryIterationBlocklistCheck,
+             "FileSystemAccessDirectoryIterationBlocklistCheck",
+             base::FEATURE_ENABLED_BY_DEFAULT);
+
 AwFeatureOverrides::AwFeatureOverrides(base::FeatureList& feature_list)
     : feature_list_(feature_list) {}
 
@@ -89,6 +95,8 @@ void AwFieldTrials::RegisterFeatureOverrides(base::FeatureList* feature_list) {
   }
   internal::AwFeatureOverrides aw_feature_overrides(*feature_list);
 
+  aw_feature_overrides.EnableFeature(::features::kWebViewFrameRateHints);
+
   // Disable third-party storage partitioning on WebView.
   aw_feature_overrides.DisableFeature(
       net::features::kThirdPartyStoragePartitioning);
@@ -292,4 +300,9 @@ void AwFieldTrials::RegisterFeatureOverrides(base::FeatureList* feature_list) {
 
   // Disable Topics on WebView.
   aw_feature_overrides.DisableFeature(blink::features::kBrowsingTopics);
+
+  // Temporarily turn off kFileSystemAccessDirectoryIterationBlocklistCheck for
+  // a kill switch. https://crbug.com/393606977
+  aw_feature_overrides.DisableFeature(
+      internal::kFileSystemAccessDirectoryIterationBlocklistCheck);
 }