Add flag to enable immersive fullscreen for v2 apps

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 9785e4b09ca901eb0816c4c5516324116a8497be..a8171bd30bdf07e160a93dd3b44829853b6070b4 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6541,6 +6541,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_DOCKED_WINDOWS_DESCRIPTION" desc="Description for the flag to disable docked windows feature.">
         Turns off docking of windows near screen edges, a feature that provides an easier way to interact with panel and other small windows.
       </message>
+      <message name="IDS_FLAGS_APP_IMMERSIVE_FULLSCREEN_NAME" desc="Name for the flag to enable immersive fullscreen for apps.">
+        Enable immersive fullscreen for apps.
+      </message>
+      <message name="IDS_FLAGS_APP_IMMERSIVE_FULLSCREEN_DESCRIPTION" desc="Description for the flag enable immersive fullscreen for apps.">
+        Sets app windows to use immersive fullscreen when fullscreening an app via the F4 key.
+      </message>
       <message name="IDS_FLAGS_SHOW_SHELF_ALIGNMENT_MENU_NAME" desc="Name for the flag to show a menu that lets you change the alignment of the shelf.">
         Show shelf alignment menu.
       </message>