Revert "Do not kill recently killed ARC processes again"

chrome/browser/memory/tab_manager_delegate_chromeos.h

Index: chrome/browser/memory/tab_manager_delegate_chromeos.h
diff --git a/chrome/browser/memory/tab_manager_delegate_chromeos.h b/chrome/browser/memory/tab_manager_delegate_chromeos.h
index 07cad6f423b0447bc5a626fc936bae4c2f6773d3..ec9d4cad972b986ccc181849f91ccb665e3e9aca 100644
--- a/chrome/browser/memory/tab_manager_delegate_chromeos.h
+++ b/chrome/browser/memory/tab_manager_delegate_chromeos.h
@@ -6,7 +6,6 @@
 #define CHROME_BROWSER_MEMORY_TAB_MANAGER_DELEGATE_CHROMEOS_H_
 
 #include <memory>
-#include <string>
 #include <utility>
 #include <vector>
 
@@ -79,11 +78,6 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   // Called when the timer fires, sets oom_adjust_score for all renderers.
   void AdjustOomPriorities(const TabStatsList& tab_list);
 
-  // Returns true if the process has recently been killed.
-  // Virtual for unit testing.
-  virtual bool IsRecentlyKilledArcProcess(const std::string& process_name,
-                                          const base::TimeTicks& now);
-
  protected:
   // Kills an ARC process. Returns true if the kill request is successfully sent
   // to Android. Virtual for unit testing.
@@ -93,14 +87,11 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   // Virtual for unit testing.
   virtual bool KillTab(int64_t tab_id);
 
-  // Get debugd client instance. Virtual for unit testing.
+  // Get debugd client instance.
   virtual chromeos::DebugDaemonClient* GetDebugDaemonClient();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(TabManagerDelegateTest, CandidatesSorted);
-  FRIEND_TEST_ALL_PREFIXES(TabManagerDelegateTest, IsRecentlyKilledArcProcess);
-  FRIEND_TEST_ALL_PREFIXES(TabManagerDelegateTest,
-                           DoNotKillRecentlyKilledArcProcesses);
   FRIEND_TEST_ALL_PREFIXES(TabManagerDelegateTest, KillMultipleProcesses);
   FRIEND_TEST_ALL_PREFIXES(TabManagerDelegateTest, SetOomScoreAdj);
 
@@ -121,9 +112,6 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   // Cache OOM scores in memory.
   typedef base::hash_map<base::ProcessHandle, int> ProcessScoreMap;
 
-  // A map from an ARC process name to a monotonic timestamp when it's killed.
-  typedef base::hash_map<std::string, base::TimeTicks> KilledArcProcessesMap;
-
   // Get the list of candidates to kill, sorted by descending importance.
   static std::vector<Candidate> GetSortedCandidates(
       const TabStatsList& tab_list,
@@ -161,14 +149,6 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   // Initiates an oom priority adjustment.
   void ScheduleEarlyOomPrioritiesAdjustment();
 
-  // Returns a TimeDelta object that represents a minimum delay for killing
-  // the same ARC process again. ARC processes sometimes respawn right after
-  // being killed. In that case, killing them every time is just a waste of
-  // resources.
-  static constexpr base::TimeDelta GetArcRespawnKillDelay() {
-    return base::TimeDelta::FromSeconds(60);
-  }
-
   // Holds a reference to the owning TabManager.
   const base::WeakPtr<TabManager> tab_manager_;
 
@@ -185,9 +165,6 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   // Map maintaining the process handle - oom_score mapping.
   ProcessScoreMap oom_score_map_;
 
-  // Map maintaing ARC process names and their last killed time.
-  KilledArcProcessesMap recently_killed_arc_processes_;
-
   // Util for getting system memory status.
   std::unique_ptr<TabManagerDelegate::MemoryStat> mem_stat_;