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 d40d15d965d877336328a73217b7d48658eb943f..7c051144eb0762e7020cfee1f51883053d1ccd10 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 enable docked windows feature.">
         Turns on 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>