[Offline Prefetch] Create a new JobScheduler task to wake up for net activity.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index eb6fc5223f41ad79fe73e0c079b72efb07492838..9775b8a1e4dc03aafa75b62d204c3da451f15bcd 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -2888,6 +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/prefetch_background_task.cc",
+      "android/offline_pages/prefetch/prefetch_background_task.h",
       "android/offline_pages/prefetch_service_factory.cc",
       "android/offline_pages/prefetch_service_factory.h",
       "android/offline_pages/prerender_adapter.cc",
@@ -4180,6 +4182,7 @@ if (is_android) {
       "../android/java/src/org/chromium/chrome/browser/offlinepages/SavePageRequest.java",
       "../android/java/src/org/chromium/chrome/browser/offlinepages/downloads/OfflinePageDownloadBridge.java",
       "../android/java/src/org/chromium/chrome/browser/offlinepages/downloads/OfflinePageNotificationBridge.java",
+      "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTask.java",
       "../android/java/src/org/chromium/chrome/browser/omnibox/AnswersImage.java",
       "../android/java/src/org/chromium/chrome/browser/omnibox/AutocompleteController.java",
       "../android/java/src/org/chromium/chrome/browser/omnibox/OmniboxPrerender.java",