Add PurgeMemory() method for ChildMemoryCoordinator.mojom

content/child/memory/child_memory_coordinator_impl.h

Index: content/child/memory/child_memory_coordinator_impl.h
diff --git a/content/child/memory/child_memory_coordinator_impl.h b/content/child/memory/child_memory_coordinator_impl.h
index ccac9b4180371603651b52b1ac2e54c8b8684ae9..04b7576dfc3bba4fad2697203b741f0e283f0971 100644
--- a/content/child/memory/child_memory_coordinator_impl.h
+++ b/content/child/memory/child_memory_coordinator_impl.h
@@ -35,11 +35,9 @@ class CONTENT_EXPORT ChildMemoryCoordinatorImpl
                              ChildMemoryCoordinatorDelegate* delegate);
   ~ChildMemoryCoordinatorImpl() override;
 
-  // Requests purging memory to clients.
-  void PurgeMemory();
-
   // mojom::ChildMemoryCoordinator implementations:
   void OnStateChange(mojom::MemoryState state) override;
+  void PurgeMemory() override;
 
  protected:
   ChildMemoryCoordinatorDelegate* delegate() { return delegate_; }