Moves LowMemoryObserver into chromeos and renames

chrome/browser/chromeos/memory/oom_priority_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_MEMORY_OOM_PRIORITY_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_MEMORY_OOM_PRIORITY_MANAGER_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process.h"
 #include "base/string16.h"
 #include "base/synchronization/lock.h"
 #include "base/time.h"
 #include "base/timer.h"
+#include "chromeos/memory/low_memory_listener_delegate.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 class GURL;
 
 namespace chromeos {
 
-class LowMemoryObserver;
+class LowMemoryListener;
 
 // The OomPriorityManager periodically checks (see
 // ADJUSTMENT_INTERVAL_SECONDS in the source) the status of renderers
 // and adjusts the out of memory (OOM) adjustment value (in
 // /proc/<pid>/oom_score_adj) of the renderers so that they match the
 // algorithm embedded here for priority in being killed upon OOM
 // conditions.
 //
 // The algorithm used favors killing tabs that are not selected, not pinned,
 // and have been idle for longest, in that order of priority.
-class OomPriorityManager : public content::NotificationObserver {
+class OomPriorityManager : public content::NotificationObserver,
+                           public LowMemoryListenerDelegate {
  public:
   OomPriorityManager();
   virtual ~OomPriorityManager();
 
   // Number of discard events since Chrome started.
   int discard_count() const { return discard_count_; }
 
   // See member comment.
   bool recent_tab_discard() const { return recent_tab_discard_; }
 
@@ skipping 66 matching lines @@
   void AdjustOomPrioritiesOnFileThread(TabStatsList stats_list);
 
   // Posts AdjustFocusedTabScore task to the file thread.
   void OnFocusTabScoreAdjustmentTimeout();
 
   // Sets the score of the focused tab to the least value.
   void AdjustFocusedTabScoreOnFileThread();
 
   static bool CompareTabStats(TabStats first, TabStats second);
 
+  // NotificationObserver overrides:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // LowMemoryListenerDelegate overrides:
+  virtual void OnMemoryLow() OVERRIDE;
+
   base::RepeatingTimer<OomPriorityManager> timer_;
   base::OneShotTimer<OomPriorityManager> focus_tab_score_adjust_timer_;
   base::RepeatingTimer<OomPriorityManager> recent_tab_discard_timer_;
   content::NotificationRegistrar registrar_;
 
   // This lock is for pid_to_oom_score_ and focus_tab_pid_.
   base::Lock pid_to_oom_score_lock_;
   // map maintaining the process - oom_score mapping.
   typedef base::hash_map<base::ProcessHandle, int> ProcessScoreMap;
   ProcessScoreMap pid_to_oom_score_;
   base::ProcessHandle focused_tab_pid_;
 
   // Observer for the kernel low memory signal.  NULL if tab discarding is
   // disabled.
-  scoped_ptr<LowMemoryObserver> low_memory_observer_;
+  scoped_ptr<LowMemoryListener> low_memory_listener_;
 
   // Wall-clock time when the priority manager started running.
   base::TimeTicks start_time_;
 
   // Wall-clock time of last tab discard during this browsing session, or 0 if
   // no discard has happened yet.
   base::TimeTicks last_discard_time_;
 
   // Wall-clock time of last priority adjustment, used to correct the above
   // times for discontinuities caused by suspend/resume.
   base::TimeTicks last_adjust_time_;
 
   // Number of times we have discarded a tab, for statistics.
   int discard_count_;
 
   // Whether a tab discard event has occurred during the last time interval,
   // used for statistics normalized by usage.
   bool recent_tab_discard_;
 
   DISALLOW_COPY_AND_ASSIGN(OomPriorityManager);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_CHROMEOS_MEMORY_OOM_PRIORITY_MANAGER_H_