Temporarily remove "last_n" from availability searches.

chrome/browser/android/offline_pages/recent_tab_helper.cc

 // Copyright (c) 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 "chrome/browser/android/offline_pages/recent_tab_helper.h"
 
 #include <queue>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/offline_pages/offline_page_mhtml_archiver.h"
 #include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
+#include "components/offline_pages/client_namespace_constants.h"
 #include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_model.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(offline_pages::RecentTabHelper);
 
 namespace {
-const char* kClientNamespace = "last_n";
 
 // Max number of pages to keep. The oldest pages that are over this count are
 // deleted before the next one is saved.
 const size_t kMaxPagesToKeep = 50;
 
 // Predicate for priority_queue used to compute the oldest pages.
 struct ComparePagesForPurge {
   bool operator()(const offline_pages::OfflinePageItem* left,
                  const offline_pages::OfflinePageItem* right) const {
     return left->creation_time > right->creation_time;
@@ skipping 148 matching lines @@
 void RecentTabHelper::ReportSnapshotCompleted() {
   snapshot_controller_->PendingSnapshotCompleted();
 }
 
 bool RecentTabHelper::IsSamePage() const {
   return web_contents() &&
          (web_contents()->GetLastCommittedURL() == snapshot_url_);
 }
 
 ClientId RecentTabHelper::client_id() const {
-  return ClientId(kClientNamespace, "");
+  return ClientId(kLastNNamespace, "");
 }
 
 void RecentTabHelper::SetArchiveFactoryForTest(
     std::unique_ptr<TestArchiveFactory> test_archive_factory) {
   test_archive_factory_ = std::move(test_archive_factory);
 }
 
 void RecentTabHelper::SetTaskRunnerForTest(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) {
   snapshot_controller_.reset(new SnapshotController(task_runner, this));
 }
 
 }  // namespace offline_pages