Modify PurgeAndSuspend to see WebContents

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 e681782791bfda6063401bb0f54e6c55ecca55f1..481aec3726199455d9caee199463a0e0b34b41f8 100644
--- a/chrome/browser/memory/tab_manager.h
+++ b/chrome/browser/memory/tab_manager.h
@@ -156,6 +156,8 @@ class TabManager : public TabStripModelObserver {
   static int64_t IdFromWebContents(content::WebContents* web_contents);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CannotSuspendTabWithMedia);
+  FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CanSuspendBasics);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, AutoDiscardable);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CanOnlyDiscardOnce);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ChildProcessNotifications);
@@ -244,6 +246,10 @@ class TabManager : public TabStripModelObserver {
   // that need to be run periodically (see comment in implementation).
   void UpdateTimerCallback();
 
+  // Goes through a list of checks to see if a tab is allowed to be purged and
+  // suspended by purge+susend backgrounded tab mechanism.
+  bool CanPurgeAndSuspendBackgroundedTab(int64_t target_web_contents_id) const;
+
   // Purges and suspends renderers in backgrounded tabs.
   void PurgeAndSuspendBackgroundedTabs();