Factor Chrome details out of update manifest fetching.

chrome/browser/extensions/extension_service.cc

Index: chrome/browser/extensions/extension_service.cc
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index dee4596c0957a91fe46dd672bdb2ccb9b96c9ece..38a71f669cc1c949e4140b95aa43d88683f2ad28 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -37,6 +37,7 @@
 #include "chrome/browser/extensions/permissions_updater.h"
 #include "chrome/browser/extensions/shared_module_service.h"
 #include "chrome/browser/extensions/unpacked_installer.h"
+#include "chrome/browser/extensions/updater/chrome_manifest_fetch_data_delegate.h"
 #include "chrome/browser/extensions/updater/extension_cache.h"
 #include "chrome/browser/extensions/updater/extension_downloader.h"
 #include "chrome/browser/extensions/updater/extension_updater.h"
@@ -596,6 +597,9 @@ scoped_ptr<ExtensionDownloader> ExtensionService::CreateExtensionDownloader(
       delegate,
       profile_->GetRequestContext()));
   downloader->SetWebstoreIdentityProvider(identity_provider.Pass());
+  downloader->SetManifestFetchDataDelegate(
+      make_scoped_ptr<extensions::ManifestFetchDataDelegate>(
+          new ChromeManifestFetchDataDelegate()));
 #endif
   return downloader.Pass();
 }