Add MemoryCoordinatorImpl::OnChildVisibilityChanged()

content/browser/memory/memory_coordinator_impl.h

Index: content/browser/memory/memory_coordinator_impl.h
diff --git a/content/browser/memory/memory_coordinator_impl.h b/content/browser/memory/memory_coordinator_impl.h
index 7bf66b16c0b172caace37d0f6099d1afac820cf5..4b63fb4cc38d88fafcf566aba4e8a951b7e1c36e 100644
--- a/content/browser/memory/memory_coordinator_impl.h
+++ b/content/browser/memory/memory_coordinator_impl.h
@@ -160,6 +160,7 @@ class CONTENT_EXPORT MemoryCoordinatorImpl : public base::MemoryCoordinator,
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorWithServiceWorkerTest,
                            CannotSuspendRendererWithServiceWorker);
 #endif
+  FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, OnChildVisibilityChanged);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, CalculateNextCondition);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, UpdateCondition);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, SetMemoryStateForTesting);
@@ -171,6 +172,9 @@ class CONTENT_EXPORT MemoryCoordinatorImpl : public base::MemoryCoordinator,
   // Called when ChildMemoryCoordinator calls AddChild().
   void OnChildAdded(int render_process_id);
 
+  // Called when visibility of a child process is changed.
+  void OnChildVisibilityChanged(int render_process_id, bool is_visible);
+
   // Called by SetChildMemoryState() to determine a child memory state based on
   // the current status of the child process.
   MemoryState OverrideState(MemoryState memroy_state, const ChildInfo& child);