Purge once random minutes(between 30min and 60min) after backgrounded.

chrome/browser/memory/tab_manager_unittest.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 <algorithm>
 #include <map>
 #include <vector>
 
@@ skipping 654 matching lines @@
   EXPECT_FALSE(tm.under_memory_pressure_);
   EXPECT_EQ(0u, task_runner->size());
   EXPECT_EQ(0u, tm.notified_renderers_.size());
 
 
   // Clean up the tabstrip.
   tabstrip.CloseAllTabs();
   ASSERT_TRUE(tabstrip.empty());
 }
 
-TEST_F(TabManagerTest, NextPurgeAndSuspendState) {
+TEST_F(TabManagerTest, DefaultTimeToPurgeInCorrectRange) {
+  TabManager tab_manager;
+  base::TimeDelta time_to_purge =
+      tab_manager.GetTimeToPurge(TabManager::kDefaultMinTimeToPurge);
+  EXPECT_GE(time_to_purge, base::TimeDelta::FromMinutes(30));
+  EXPECT_LT(time_to_purge, base::TimeDelta::FromMinutes(60));
+}
+
+TEST_F(TabManagerTest, ShouldPurgeAtDefaultTime) {
   TabManager tab_manager;
   TabStripDummyDelegate delegate;
   TabStripModel tabstrip(&delegate, profile());
   tabstrip.AddObserver(&tab_manager);
 
   WebContents* test_contents = CreateWebContents();
   tabstrip.AppendWebContents(test_contents, false);
 
-  // Use default time-to-first-purge  defined in TabManager.
-  base::TimeDelta threshold = TabManager::kDefaultTimeToFirstPurge;
   base::SimpleTestTickClock test_clock;
+  tab_manager.set_test_tick_clock(&test_clock);
 
+  tab_manager.GetWebContentsData(test_contents)->set_is_purged(false);
   tab_manager.GetWebContentsData(test_contents)
-      ->SetPurgeAndSuspendState(TabManager::RUNNING);
+      ->SetLastInactiveTime(test_clock.NowTicks());
   tab_manager.GetWebContentsData(test_contents)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
+      ->set_time_to_purge(base::TimeDelta::FromMinutes(1));
 
-  // Wait 30 minutes and verify that the tab is still RUNNING.
-  test_clock.Advance(base::TimeDelta::FromMinutes(30));
-  EXPECT_EQ(TabManager::RUNNING,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
+  // Wait 1 minute and verify that the tab is still not to be purged.
+  test_clock.Advance(base::TimeDelta::FromMinutes(1));
+  EXPECT_FALSE(tab_manager.ShouldPurgeAtTime(test_contents));
 
-  // Wait another second and verify that it is now SUSPENDED.
+  // Wait another 1 second and verify that it should be purged now .
   test_clock.Advance(base::TimeDelta::FromSeconds(1));
-  EXPECT_EQ(TabManager::SUSPENDED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
+  EXPECT_TRUE(tab_manager.ShouldPurgeAtTime(test_contents));
 
+  tab_manager.GetWebContentsData(test_contents)->set_is_purged(true);
   tab_manager.GetWebContentsData(test_contents)
-      ->SetPurgeAndSuspendState(TabManager::SUSPENDED);
-  tab_manager.GetWebContentsData(test_contents)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
+      ->SetLastInactiveTime(test_clock.NowTicks());
 
-  test_clock.Advance(base::TimeDelta::FromSeconds(1200));
-  EXPECT_EQ(TabManager::SUSPENDED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
-
-  test_clock.Advance(base::TimeDelta::FromSeconds(1));
-  EXPECT_EQ(TabManager::RESUMED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
-
-  tab_manager.GetWebContentsData(test_contents)
-      ->SetPurgeAndSuspendState(TabManager::RESUMED);
-  tab_manager.GetWebContentsData(test_contents)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
-
-  test_clock.Advance(base::TimeDelta::FromSeconds(10));
-  EXPECT_EQ(TabManager::RESUMED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
-
-  test_clock.Advance(base::TimeDelta::FromSeconds(1));
-  EXPECT_EQ(TabManager::SUSPENDED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
+  // Wait 1 day and verify that the tab is still be purged.
+  test_clock.Advance(base::TimeDelta::FromMinutes(60 * 24));

[Wez, 2017/03/03 21:06:51]

You can use FromHours(24) here.

[tasak, 2017/03/06 10:30:19]

Done.

+  EXPECT_FALSE(tab_manager.ShouldPurgeAtTime(test_contents));
 
   // Clean up the tabstrip.
   tabstrip.CloseAllTabs();
   EXPECT_TRUE(tabstrip.empty());
 }
 
-TEST_F(TabManagerTest, ActivateTabResetPurgeAndSuspendState) {
+TEST_F(TabManagerTest, ActivateTabResetPurgeState) {
   TabManager tab_manager;
   TabStripDummyDelegate delegate;
   TabStripModel tabstrip(&delegate, profile());
   tabstrip.AddObserver(&tab_manager);
 
   WebContents* tab1 = CreateWebContents();
   WebContents* tab2 = CreateWebContents();
   tabstrip.AppendWebContents(tab1, true);
   tabstrip.AppendWebContents(tab2, false);
 
   base::SimpleTestTickClock test_clock;
 
-  // Initially PurgeAndSuspend state should be RUNNING.
-  EXPECT_EQ(TabManager::RUNNING,
-            tab_manager.GetWebContentsData(tab2)->GetPurgeAndSuspendState());
+  // Initially PurgeAndSuspend state should be NOT_PURGED.
+  EXPECT_FALSE(tab_manager.GetWebContentsData(tab2)->is_purged());
 
-  tab_manager.GetWebContentsData(tab2)->SetPurgeAndSuspendState(
-      TabManager::SUSPENDED);
-  tab_manager.GetWebContentsData(tab2)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
+  tab_manager.GetWebContentsData(tab2)->set_is_purged(true);

[Wez, 2017/03/03 21:06:51]

You're not actually going through the normal purge flow; you might prefer to
configure the tab to purge after one minute, Advance() time, verify that it
purges, and then signal that it was active and verify that it is no longer
purged, for example.

[tasak, 2017/03/06 10:30:19]

Done.
However, what I want to do here is just checking if
"TabManager::ActiveTabChanged" is invoked and if set_is_purged(false) is
invoked.

+  tab_manager.GetWebContentsData(tab2)->SetLastInactiveTime(
+      test_clock.NowTicks());
 
-  // Activate tab2. Tab2's PurgeAndSuspend state should be RUNNING.
+  // Activate tab2. Tab2's PurgeAndSuspend state should be NOT_PURGED.
   tabstrip.ActivateTabAt(1, true /* user_gesture */);
-  EXPECT_EQ(TabManager::RUNNING,
-            tab_manager.GetWebContentsData(tab2)->GetPurgeAndSuspendState());
-
-  tab_manager.GetWebContentsData(tab1)->SetPurgeAndSuspendState(
-      TabManager::RESUMED);
-  tab_manager.GetWebContentsData(tab1)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
-
-  // Activate tab1. Tab1's PurgeAndSuspend state should be RUNNING.
-  tabstrip.ActivateTabAt(0, true /* user_gesture */);
-  EXPECT_EQ(TabManager::RUNNING,
-            tab_manager.GetWebContentsData(tab1)->GetPurgeAndSuspendState());
+  EXPECT_FALSE(tab_manager.GetWebContentsData(tab2)->is_purged());
 
   // Clean up the tabstrip.
   tabstrip.CloseAllTabs();
   EXPECT_TRUE(tabstrip.empty());

[Wez, 2017/03/03 21:06:51]

nit: Do you need to expect this? Isn't it part of the CloseAllTabs() API
contract?

[tasak, 2017/03/06 10:30:19]

Removed.

 }
 
 }  // namespace memory