Add the about_page key to shared_module manifest

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 d7d616cb57408771604c5dc19c65bc493d341255..3176628f6c0b87042844b23422ce6b43aca122f8 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -2187,6 +2187,12 @@ Even if you have downloaded files from this website before, the website might ha
           Uninstall
         </message>
       </if>
+      <message name="IDS_APPLICATION_INFO_IMPORTED_MODULES_TITLE_TEXT" desc="Text for the title above the imported modules for the app. Imported modules are like shared libraries that an app has used when it was built (but are not directly accessible by a user).">
+        This app imports the following modules:
+      </message>
+      <message name="IDS_APPLICATION_INFO_IMPORTED_MODULES_ABOUT_LINK_TEXT" desc="Text for the link next to each imported module that goes to the About page for that module. The About page may include things such as open-source and copyright licenses for the app.">
+        About
+      </message>
       <message name="IDS_APPLICATION_INFO_REQUIRED_PERMISSIONS_TEXT" desc="Heading for the required permissions for the app (the permissions that the user must grant the app upon installation).">
         Required
       </message>
@@ -4544,6 +4550,9 @@ Make sure you do not expose any sensitive information.
       <message name="IDS_EXTENSION_LOAD_OPTIONS_PAGE_FAILED" desc="">
         Could not load options page '<ph name="OPTIONS_PAGE">$1<ex>page.html</ex></ph>'.
       </message>
+      <message name="IDS_EXTENSION_LOAD_ABOUT_PAGE_FAILED" desc="">
+        Could not load about page '<ph name="ABOUT_PAGE">$1<ex>page.html</ex></ph>'.
+      </message>
       <if expr="is_win">
         <message name="IDS_EXTENSION_UNPACK_FAILED" desc="On windows, it is possible to mount a disk without the root of that disk having a drive letter.  The sandbox does not support this. See crbug/49530 .">
           Can not unpack extension.  To safely unpack an extension, there must be a path to your profile directory that starts with a drive letter and does not contain a junction, mount point, or symlink.  No such path exists for your profile.