Last_n: disable on Svelte devices.

chrome/browser/android/offline_pages/recent_tab_helper.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_OFFLINE_PAGES_RECENT_TAB_HELPER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_RECENT_TAB_HELPER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 69 matching lines @@
   // Note #2: Currently this method only accepts download requests from the
   // downloads namespace.
   void ObserveAndDownloadCurrentPage(const ClientId& client_id,
                                      int64_t request_id);
 
  private:
   struct SnapshotProgressInfo;
 
   explicit RecentTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<RecentTabHelper>;
+  FRIEND_TEST_ALL_PREFIXES(RecentTabHelperTest, LastNDisabledOnSvelte);

[Dmitry Titov, 2017/02/16 20:58:41]

Could we add a getter on Delegate to return whether it's a low end device? We
already use Delegate here for dependency injection during testing, so would be
nice to only have one method.

[carlosk, 2017/02/16 21:48:16]

Done. I also added a getter for the initial test delegate created by
RecentTabHelperTest::SetUp as it was unnecessary to create a new one in 3 test
cases (including this new one).

 
   bool EnsureInitialized();
   void ContinueSnapshotWithIdsToPurge(SnapshotProgressInfo* snapshot_info,
                                       const std::vector<int64_t>& page_ids);
   void ContinueSnapshotAfterPurge(SnapshotProgressInfo* snapshot_info,
                                   OfflinePageModel::DeletePageResult result);
   void SavePageCallback(SnapshotProgressInfo* snapshot_info,
                         OfflinePageModel::SavePageResult result,
                         int64_t offline_id);
   void ReportSnapshotCompleted(SnapshotProgressInfo* snapshot_info,
@@ skipping 45 matching lines @@
 
   // Set at each navigation to control if last_n should save snapshots of the
   // current page being loaded.
   bool last_n_listen_to_tab_hidden_ = false;
 
   // Track the page quality status of the last saved snapshot for the current
   // page. It is generally reset upon new navigations.
   SnapshotController::PageQuality last_n_latest_saved_quality_ =
       SnapshotController::PageQuality::POOR;
 
+  // Cached value of whether low end device. Overwritable for testing.
+  bool is_low_end_device_;
+
   base::WeakPtrFactory<RecentTabHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RecentTabHelper);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_RECENT_TAB_HELPER_H_