Only show Last N Pages in the UI when the corresponding tab is visible.

components/ntp_snippets/offline_pages/offline_pages_test_utils.cc

 // Copyright 2016 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/ntp_snippets/offline_pages/offline_pages_test_utils.h"
 
 #include <iterator>
 #include <vector>
 
 #include "base/guid.h"
@@ skipping 41 matching lines @@
 }
 
 bool FakeOfflinePageModel::is_loaded() const {
   return is_loaded_;
 }
 
 void FakeOfflinePageModel::set_is_loaded(bool value) {
   is_loaded_ = value;
 }
 
+OfflinePageItem CreateDummyOfflinePageItem(
+    int id,
+    const offline_pages::ClientId& client_id) {
+  std::string id_string = base::IntToString(id);
+  return OfflinePageItem(
+      GURL("http://dummy.com/" + id_string), id, client_id,
+      base::FilePath::FromUTF8Unsafe("some/folder/test" + id_string + ".mhtml"),
+      0, base::Time::Now());
+}
+
 OfflinePageItem CreateDummyOfflinePageItem(int id,
                                            const std::string& name_space) {
-  std::string id_string = base::IntToString(id);
-  return OfflinePageItem(
-      GURL("http://dummy.com/" + id_string), id,
-      ClientId(name_space, base::GenerateGUID()),
-      base::FilePath::FromUTF8Unsafe("some/folder/test" + id_string + ".mhtml"),
-      0, base::Time::Now());
+  return CreateDummyOfflinePageItem(id,
+                                    ClientId(name_space, base::GenerateGUID()));
 }
 
 void CaptureDismissedSuggestions(
     std::vector<ContentSuggestion>* captured_suggestions,
     std::vector<ContentSuggestion> dismissed_suggestions) {
   std::move(dismissed_suggestions.begin(), dismissed_suggestions.end(),
             std::back_inserter(*captured_suggestions));
 }
 
 }  // namespace test
 }  // namespace ntp_snippets