Implementing TabManager extensions API Discard Function.

chrome/browser/memory/tab_manager.h

Index: chrome/browser/memory/tab_manager.h
diff --git a/chrome/browser/memory/tab_manager.h b/chrome/browser/memory/tab_manager.h
index cd5c3480417bf76976c8a3849ae4d0e5fe6c5057..7719fbbb54fa375775961903e87d1b27e83db4f7 100644
--- a/chrome/browser/memory/tab_manager.h
+++ b/chrome/browser/memory/tab_manager.h
@@ -108,6 +108,10 @@ class TabManager : public TabStripModelObserver {
   // that got discarded. This value is mostly useful during testing.
   content::WebContents* DiscardTabById(int64_t target_web_contents_id);
 
+  // If |contents| is null, discards the least important tab using DiscardTab().

[Georges Khalil, 2016/07/19 19:39:45]

Start comment by explaining that this is the function that will be called by the
extensions API.

[Anderson Silva, 2016/07/19 20:28:42]

Done.

+  // Otherwise discards the given contents.
+  content::WebContents* DiscardTabByExtension(content::WebContents* contents);
+
   // Log memory statistics for the running processes, then discards a tab.
   // Tab discard happens sometime later, as collecting the statistics touches
   // multiple threads and takes time.
@@ -128,6 +132,9 @@ class TabManager : public TabStripModelObserver {
   void AddObserver(TabManagerObserver* observer);
   void RemoveObserver(TabManagerObserver* observer);
 
+  // Used in tets to change the protection time of the tabs.

[Georges Khalil, 2016/07/19 19:39:45]

nit: tets -> tests.

+  void set_minimum_protection_time_for_tests(unsigned int time_seconds);

[Georges Khalil, 2016/07/19 19:39:45]

This should take a base::TimeDelta so there's no confusion.

[Anderson Silva, 2016/07/19 20:28:42]

Done.

+
  private:
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CanOnlyDiscardOnce);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ChildProcessNotifications);
@@ -257,7 +264,7 @@ class TabManager : public TabStripModelObserver {
   void DoChildProcessDispatch();
 
   // Implementation of DiscardTab.

[Georges Khalil, 2016/07/19 19:39:45]

Add comment about return value.

-  bool DiscardTabImpl();
+  content::WebContents* DiscardTabImpl();
 
   // Returns true if tabs can be discarded only once.
   bool CanOnlyDiscardOnce();