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, NextPurgeState) {

[Wez, 2017/03/02 02:28:32]

NextPurgeState was the name of the function - you really want the test name to
describe what you're testing.

In this case I think you want two separate tests:

1. Do we choose an appropriate time to purge?
- If I notify TabManager that a tab was backgrounded, does it get a
time-to-purge in the right default range?

2. Do we respect the configured time-to-purge?
- If I set a particular time-to-purge, does the ShouldPurge result change at the
right time?

[tasak, 2017/03/02 09:22:47]

Renamed to be ShouldPurgeAtDefaultTime.
I added a unit test to see GetTimeToPurge.
I updated ShouldPurgedAtDefaultTime.

I also added a new browser test.

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

Acknowledged.

   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;

[Wez, 2017/03/02 02:28:32]

You probably want to tab_manager.set_test_tick_clock() with this here.

[tasak, 2017/03/02 09:22:47]

Done.

 
+  tab_manager.GetWebContentsData(test_contents)->SetPurgeState(false);
   tab_manager.GetWebContentsData(test_contents)
-      ->SetPurgeAndSuspendState(TabManager::RUNNING);
+      ->SetLastInactiveTime(test_clock.NowTicks());
+  // Use default min-time-to-purge defined in TabManager.
+  base::TimeDelta time_to_purge =
+      tab_manager.GetTimeToPurge(TabManager::kDefaultMinTimeToPurge);
+  tab_manager.GetWebContentsData(test_contents)->SetTimeToPurge(time_to_purge);
+
+  // Wait 30 minutes and verify that the tab is still NOT_PURGED.
+  test_clock.Advance(base::TimeDelta::FromMinutes(30));
+  EXPECT_FALSE(
+      tab_manager.ShouldPurgeAtTime(test_contents, test_clock.NowTicks()));
+
+  // Wait another 30 minutes and verify that it should be purged now .
+  test_clock.Advance(base::TimeDelta::FromMinutes(30));
+  EXPECT_TRUE(
+      tab_manager.ShouldPurgeAtTime(test_contents, test_clock.NowTicks()));
+
+  tab_manager.GetWebContentsData(test_contents)->SetPurgeState(true);
   tab_manager.GetWebContentsData(test_contents)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
+      ->SetLastInactiveTime(test_clock.NowTicks());
 
-  // 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 another second and verify that it is now SUSPENDED.
-  test_clock.Advance(base::TimeDelta::FromSeconds(1));
-  EXPECT_EQ(TabManager::SUSPENDED,
-            tab_manager.GetNextPurgeAndSuspendState(
-                test_contents, test_clock.NowTicks(), threshold));
-
-  tab_manager.GetWebContentsData(test_contents)
-      ->SetPurgeAndSuspendState(TabManager::SUSPENDED);
-  tab_manager.GetWebContentsData(test_contents)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(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));
+  test_clock.Advance(base::TimeDelta::FromMinutes(120));
+  EXPECT_FALSE(
+      tab_manager.ShouldPurgeAtTime(test_contents, test_clock.NowTicks()));
 
   // 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)->IsPurged());
 
-  tab_manager.GetWebContentsData(tab2)->SetPurgeAndSuspendState(
-      TabManager::SUSPENDED);
-  tab_manager.GetWebContentsData(tab2)
-      ->SetLastPurgeAndSuspendModifiedTimeForTesting(test_clock.NowTicks());
+  tab_manager.GetWebContentsData(tab2)->SetPurgeState(true);
+  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)->IsPurged());
 
   // Clean up the tabstrip.
   tabstrip.CloseAllTabs();
   EXPECT_TRUE(tabstrip.empty());
 }
 
 }  // namespace memory