Add flag to enable syncfs directory support to about:flags.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 2f68e34fe3526c7cdcff879bf952f89830c318da..0620bf33572e3b9901b12daae5f28f29550a5f7c 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -7227,6 +7227,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_DEFAULT_TILE_HEIGHT_VENTI" desc="">
         1024
       </message>
+      <message name="IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_NAME" desc="Name of the flag to enable syncfs direcory support.">
+        Enable Syncfs directory operation.
+      </message>
+      <message name="IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_DESCRIPTION" desc="Description of the flag to enable syncfs directory support.">
+        Enables directory support for sync filesystem.
+      </message>
 
       <!-- Crashes -->
       <message name="IDS_CRASHES_TITLE" desc="Title for the chrome://crashes page.">