Discardable property support on TabManager

chrome/browser/memory/tab_manager_web_contents_data.h

 // Copyright 2015 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_WEB_CONTENTS_DATA_H_
 #define CHROME_BROWSER_MEMORY_TAB_MANAGER_WEB_CONTENTS_DATA_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "chrome/browser/memory/tab_manager.h"
@@ skipping 54 matching lines @@
   void SetLastInactiveTime(base::TimeTicks timestamp);
 
   // Copies the discard state from |old_contents| to |new_contents|.
   static void CopyState(content::WebContents* old_contents,
                         content::WebContents* new_contents);
 
   // Used to set the test TickClock, which then gets used by NowTicks(). See
   // |test_tick_clock_| for more details.
   void set_test_tick_clock(base::TickClock* test_tick_clock);
 
+  // Returns the auto discardable state of the tab.
+  // See tab_manager.h for more information.
+  bool IsAutoDiscardable();
+
+  // Sets/clears the auto discardable state of the tab.
+  void SetAutoDiscardableState(bool state);
+
  private:
   // Needed to access tab_data_.
   FRIEND_TEST_ALL_PREFIXES(TabManagerWebContentsDataTest, CopyState);
 
   struct Data {
     Data();
     bool operator==(const Data& right) const;
     bool operator!=(const Data& right) const;
 
     // TODO(georgesak): fix naming (no underscore).
     // Is the tab currently discarded?
     bool is_discarded_;
     // Number of times the tab has been discarded.
     int discard_count_;
     // Is the tab playing audio?
     bool is_recently_audible_;
     // Last time the tab started or stopped playing audio (we record the
     // transition time).
     base::TimeTicks last_audio_change_time_;
     // The last time the tab was discarded.
     base::TimeTicks last_discard_time_;
     // The last time the tab was reloaded after being discarded.
     base::TimeTicks last_reload_time_;
     // The last time the tab switched from being active to inactive.
     base::TimeTicks last_inactive_time_;
     // Site Engagement score (set to -1 if not available).
     double engagement_score_;
+    // Is tab eligible for auto discarding? Defaults to true.
+    bool is_auto_discardable;
   };
 
   // Returns either the system's clock or the test clock. See |test_tick_clock_|
   // for more details.
   base::TimeTicks NowTicks() const;
 
   // Contains all the needed data for the tab.
   Data tab_data_;
 
   // Pointer to a test clock. If this is set, NowTicks() returns the value of
   // this test clock. Otherwise it returns the system clock's value.
   base::TickClock* test_tick_clock_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsData);
 };
 
 }  // namespace memory
 
 #endif  // CHROME_BROWSER_MEMORY_TAB_MANAGER_WEB_CONTENTS_DATA_H_