Bug fix: Use the last hidden time for purge + suspend

chrome/browser/memory/tab_manager.cc

 // Copyright (c) 2012 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/memory/tab_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 621 matching lines @@
       stats.is_app = is_app;
       stats.is_internal_page = IsInternalPage(contents->GetLastCommittedURL());
       stats.is_media = IsMediaTab(contents);
       stats.is_pinned = model->IsTabPinned(i);
       stats.is_selected = active_model && model->IsTabSelected(i);
       stats.is_discarded = GetWebContentsData(contents)->IsDiscarded();
       stats.has_form_entry =
           contents->GetPageImportanceSignals().had_form_interaction;
       stats.discard_count = GetWebContentsData(contents)->DiscardCount();
       stats.last_active = contents->GetLastActiveTime();
+      stats.last_hidden = contents->GetLastHiddenTime();
       stats.render_process_host = contents->GetRenderProcessHost();
       stats.renderer_handle = contents->GetRenderProcessHost()->GetHandle();
       stats.child_process_host_id = contents->GetRenderProcessHost()->GetID();
 #if defined(OS_CHROMEOS)
       stats.oom_score = delegate_->GetCachedOomScore(stats.renderer_handle);
 #endif
       stats.title = contents->GetTitle();
       stats.tab_contents_id = IdFromWebContents(contents);
       stats_list->push_back(stats);
     }
@@ skipping 51 matching lines @@
   auto purge_and_suspend_time_threshold =
       NowTicks() - base::TimeDelta::FromSeconds(purge_and_suspend_time);
   auto tab_stats = GetUnsortedTabStats();
   for (auto& tab : tab_stats) {
     if (!tab.render_process_host->IsProcessBackgrounded())
       continue;
     // TODO(hajimehoshi): Now calling PurgeAndSuspend is implemented without
     // timers for simplicity, so PurgeAndSuspend is called even after the
     // renderer is purged and suspended once. This should be replaced with
     // timers if we want necessary and sufficient signals.
-    if (tab.last_active > purge_and_suspend_time_threshold)
+    if (tab.last_hidden > purge_and_suspend_time_threshold)
       continue;
     if (!CanSuspendBackgroundedRenderer(tab.child_process_host_id))
       continue;
     tab.render_process_host->PurgeAndSuspend();
   }
 }
 
 WebContents* TabManager::DiscardWebContentsAt(int index, TabStripModel* model) {
   // Can't discard active index.
   if (model->active_index() == index)
@@ skipping 235 matching lines @@
   // platform.
   std::string allow_multiple_discards = variations::GetVariationParamValue(
       features::kAutomaticTabDiscarding.name, "AllowMultipleDiscards");
   return (allow_multiple_discards != "true");
 #else
   return false;
 #endif
 }
 
 }  // namespace memory