[Offline Pages] Set up the initial prefetching service.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index cda77e2c4d0a884b4fe3fa9842735e571fca09bc..eb6fc5223f41ad79fe73e0c079b72efb07492838 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -1507,6 +1507,7 @@ split_static_library("browser") {
     "//components/offline_pages/core",
     "//components/offline_pages/core/background:background_offliner",
     "//components/offline_pages/core/downloads:offline_pages_ui_adapter",
+    "//components/offline_pages/core/prefetch",
     "//components/offline_pages/core/recent_tabs",
     "//components/offline_pages/core/request_header:request_header",
     "//components/omnibox/browser",
@@ -2887,6 +2888,8 @@ split_static_library("browser") {
       "android/offline_pages/offliner_factory.h",
       "android/offline_pages/offliner_helper.cc",
       "android/offline_pages/offliner_helper.h",
+      "android/offline_pages/prefetch_service_factory.cc",
+      "android/offline_pages/prefetch_service_factory.h",
       "android/offline_pages/prerender_adapter.cc",
       "android/offline_pages/prerender_adapter.h",
       "android/offline_pages/prerendering_loader.cc",
@@ -2897,6 +2900,8 @@ split_static_library("browser") {
       "android/offline_pages/recent_tab_helper.h",
       "android/offline_pages/request_coordinator_factory.cc",
       "android/offline_pages/request_coordinator_factory.h",
+      "android/offline_pages/suggested_articles_observer.cc",
+      "android/offline_pages/suggested_articles_observer.h",
       "android/omnibox/answers_image_bridge.cc",
       "android/omnibox/answers_image_bridge.h",
       "android/omnibox/autocomplete_controller_android.cc",