Discardable property support on TabManager

chrome/browser/memory/tab_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_MEMORY_TAB_MANAGER_H_
 #define CHROME_BROWSER_MEMORY_TAB_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 110 matching lines @@
   void set_test_tick_clock(base::TickClock* test_tick_clock);
 
   // Returns the list of the stats for all renderers. Must be called on the UI
   // thread.
   TabStatsList GetUnsortedTabStats();
 
   // Add/remove observers.
   void AddObserver(TabManagerObserver* observer);
   void RemoveObserver(TabManagerObserver* observer);
 
+  // Returns true if the tab is auto discardable by auto discarding feature.

[Georges Khalil, 2016/07/22 15:07:57]

nit: reword the comment

Returns the auto discardable state of the tab. When true, the tab is eligible to
be automatically discarded when critical memory pressure hits, otherwise the tab
is ignored and will never be automatically discarded. Note that this property
doesn't block the discarding of the tab via other methods (about:discards for
instance).

[Anderson Silva, 2016/07/22 15:34:51]

Done.

+  bool IsTabAutoDiscardable(content::WebContents* contents) const;
+
+  // Sets/clears the AutoDiscardable state of the tab.
+  void SetTabAutoDiscardableState(content::WebContents* contents, bool state);

[Georges Khalil, 2016/07/22 15:07:57]

nit: s/AutoDiscardable/auto discardable

[Anderson Silva, 2016/07/22 15:34:51]

Done.

+
  private:
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CanOnlyDiscardOnce);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ChildProcessNotifications);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, Comparator);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, DiscardedTabKeepsLastActiveTime);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, DiscardWebContentsAt);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, InvalidOrEmptyURL);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, IsInternalPage);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, OomPressureListener);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectPDFPages);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectRecentlyUsedTabs);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectVideoTabs);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ReloadDiscardedTabContextMenu);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, TabManagerBasics);
 
   // This is needed so WebContentsData can call OnDiscardedStateChange.
   friend class WebContensData;
 
   // Called by WebContentsData whenever the discard state of a WebContents
   // changes, so that observers can be informed.
   void OnDiscardedStateChange(content::WebContents* contents,
                               bool is_discarded);
 
+  // Called by WebContentsData whenever the AutoDiscardable state of a
+  // WebContents

[Georges Khalil, 2016/07/22 15:07:57]

nit: line ending.
nit: s/AutoDiscardable/auto discardable

[Anderson Silva, 2016/07/22 15:34:51]

Done.

+  // changes, so that observers can be informed.
+  void OnAutoDiscardableStateChange(content::WebContents* contents,
+                                    bool is_auto_discardable);
+
   // The time that a renderer is given to react to a memory pressure
   // notification before another renderer is also notified. This prevents all
   // renderers from receiving and acting upon notifications simultaneously,
   // which can quickly overload a system. Exposed for unittesting.
   // NOTE: This value needs to be big enough to allow a process to get over the
   // hump in responding to memory pressure, so there aren't multiple processes
   // fighting for CPU and worse, temporary memory, while trying to free things
   // up. Similarly, it shouldn't be too large otherwise it will take too long
   // for the entire system to respond. Ideally, there would be a callback from a
   // child process indicating that the message has been handled. In the meantime
@@ skipping 184 matching lines @@
 
   // Weak pointer factory used for posting delayed tasks to task_runner_.
   base::WeakPtrFactory<TabManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabManager);
 };
 
 }  // namespace memory
 
 #endif  // CHROME_BROWSER_MEMORY_TAB_MANAGER_H_