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

chrome/browser/extensions/extension_updater.cc

Index: chrome/browser/extensions/extension_updater.cc
diff --git a/chrome/browser/extensions/extension_updater.cc b/chrome/browser/extensions/extension_updater.cc
index 505796ec1660432aa216dd4afe49b2e1f26bf4d5..5c5c9801c7b9c31172992a418e5fd164ea281fa1 100644
--- a/chrome/browser/extensions/extension_updater.cc
+++ b/chrome/browser/extensions/extension_updater.cc
@@ -26,6 +26,7 @@
 #include "chrome/browser/utility_process_host.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/pref_names.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/escape.h"
@@ -46,11 +47,6 @@ using prefs::kExtensionBlacklistUpdateVersion;
 using prefs::kLastExtensionsUpdateCheck;
 using prefs::kNextExtensionsUpdateCheck;
 
-// The default URL to fall back to if an extension doesn't have an
-// update URL.
-const char kDefaultUpdateURL[] =
-    "http://clients2.google.com/service/update2/crx";
-
 // NOTE: HTTPS is used here to ensure the response from omaha can be trusted.
 // The response contains a url for fetching the blacklist and a hash value
 // for validation.
@@ -241,7 +237,7 @@ void ManifestFetchesBuilder::AddExtensionData(
   } else if (update_url.is_empty()) {
     url_stats_.no_url_count++;
     // Fill in default update URL.
-    update_url = GURL(kDefaultUpdateURL);
+    update_url = GURL(extension_urls::kGalleryUpdateURL);
   } else {
     url_stats_.other_url_count++;
   }