Only allow installation of extensions/apps with gallery update url via download from gallery

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 5f10677030a8c2411ed97e0f5a443ad335ede6a9..e7790215a1c6c68e88f764fff66100f7bda5b932 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -3373,6 +3373,9 @@ each locale. -->
       <message name="IDS_EXTENSION_DIRECTORY_NO_EXISTS" desc="Warning displayed in pack dialog when the extension directory does not exist.">
         Input directory must exist.
       </message>
+      <message name="IDS_EXTENSION_DISALLOW_NON_DOWNLOADED_GALLERY_INSTALLS" desc="Error displayed when an extension that has an update URL used by the gallery is installed when not directly downloaded from the gallery.">
+        This package can only be installed from the <ph name="CHROME_WEB_STORE">$1<ex>Chrome Web Store</ex></ph>.
+      </message>
       <message name="IDS_EXTENSION_PRIVATE_KEY_INVALID_PATH" desc="Warning displayed in pack dialog when the private key must be a valid path.">
         Input value for private key must be a valid path.
       </message>
@@ -3627,6 +3630,9 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_EXTENSION_PROMPT_ENABLE_INCOGNITO_BUTTON" desc="Text for the allow button on the extension run-in-incognito prompt">
         Allow
       </message>
+      <message name="IDS_EXTENSION_WEB_STORE_TITLE" desc="Text for the Chrome Web Store">
+        Chrome Web Store
+      </message>
 
       <!-- chrome://plugins page -->
       <message name="IDS_PLUGINS_TITLE" desc="Title for the chrome://plugins page.">