[Offline pages] CCT UMA and checks on the new background loader.

BUG=665242

Review-Url: https://codereview.chromium.org/2611133004
Cr-Commit-Position: refs/heads/master@{#443734}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 1668519..0ff9de1 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -2752,6 +2752,8 @@
       "android/offline_pages/offline_page_utils.cc",
       "android/offline_pages/offline_page_utils.h",
       "android/offline_pages/offliner_factory.h",
+      "android/offline_pages/offliner_helper.cc",
+      "android/offline_pages/offliner_helper.h",
       "android/offline_pages/prerender_adapter.cc",
       "android/offline_pages/prerender_adapter.h",
       "android/offline_pages/prerendering_loader.cc",