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

chrome/browser/memory/tab_manager_web_contents_data_unittest.cc

Index: chrome/browser/memory/tab_manager_web_contents_data_unittest.cc
diff --git a/chrome/browser/memory/tab_manager_web_contents_data_unittest.cc b/chrome/browser/memory/tab_manager_web_contents_data_unittest.cc
index d98afa8c040ba8f22578bfbdcfe61c7a0af2a4da..e8adeefb150bd2955f29af1329cf014b6f2ae585 100644
--- a/chrome/browser/memory/tab_manager_web_contents_data_unittest.cc
+++ b/chrome/browser/memory/tab_manager_web_contents_data_unittest.cc
@@ -204,25 +204,4 @@ TEST_F(TabManagerWebContentsDataTest, HistogramsInactiveToReloadTime) {
   histograms.ExpectBucketCount(kHistogramName, 12000, 1);
 }
 
-TEST_F(TabManagerWebContentsDataTest, PurgeAndSuspendState) {
-  EXPECT_EQ(TabManager::RUNNING, tab_data()->GetPurgeAndSuspendState());
-  base::TimeTicks last_modified = tab_data()->LastPurgeAndSuspendModifiedTime();
-  test_clock().Advance(base::TimeDelta::FromSeconds(5));
-  tab_data()->SetPurgeAndSuspendState(TabManager::SUSPENDED);
-  EXPECT_EQ(TabManager::SUSPENDED, tab_data()->GetPurgeAndSuspendState());
-  EXPECT_GT(tab_data()->LastPurgeAndSuspendModifiedTime(), last_modified);
-
-  last_modified = tab_data()->LastPurgeAndSuspendModifiedTime();
-  test_clock().Advance(base::TimeDelta::FromSeconds(5));
-  tab_data()->SetPurgeAndSuspendState(TabManager::RESUMED);
-  EXPECT_EQ(TabManager::RESUMED, tab_data()->GetPurgeAndSuspendState());
-  EXPECT_GT(tab_data()->LastPurgeAndSuspendModifiedTime(), last_modified);
-
-  last_modified = tab_data()->LastPurgeAndSuspendModifiedTime();
-  test_clock().Advance(base::TimeDelta::FromSeconds(5));
-  tab_data()->SetPurgeAndSuspendState(TabManager::RUNNING);
-  EXPECT_EQ(TabManager::RUNNING, tab_data()->GetPurgeAndSuspendState());
-  EXPECT_GT(tab_data()->LastPurgeAndSuspendModifiedTime(), last_modified);
-}
-
 }  // namespace memory