[Offline Pages] Add a GCMAppHandler for offline page prefetch.

chrome/browser/android/offline_pages/prefetch/suggested_articles_observer.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/offline_pages/content/suggested_articles_observer.h"
+#include "chrome/browser/android/offline_pages/prefetch/suggested_articles_observer.h"
 
 #include <unordered_set>
 
 #include "base/memory/ptr_util.h"
+#include "chrome/browser/android/offline_pages/prefetch/prefetch_service_factory.h"
 #include "components/ntp_snippets/category.h"
 #include "components/ntp_snippets/category_status.h"
-#include "components/offline_pages/content/prefetch_service_factory.h"
 #include "components/offline_pages/core/client_namespace_constants.h"
 #include "components/offline_pages/core/offline_page_feature.h"
 #include "components/offline_pages/core/prefetch/prefetch_service_impl.h"
 
 using ntp_snippets::Category;
 using ntp_snippets::ContentSuggestion;
 
 namespace offline_pages {
 
 namespace {
@@ skipping 135 matching lines @@
   }
   service->RemoveAllUnprocessedPrefetchURLs(kSuggestedArticlesNamespace);
   OnNewSuggestions(ArticlesCategory());
 }
 
 void SuggestedArticlesObserver::ContentSuggestionsServiceShutdown() {
   // No need to do anything here, we will just stop getting events.
 }
 
 }  // namespace offline_pages