memory coordinator: Add MemoryCoordinatorClient::OnPurgeMemory()

net/ssl/ssl_client_session_cache.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 NET_SSL_SSL_CLIENT_SESSION_CACHE_H_
 #define NET_SSL_SSL_CLIENT_SESSION_CACHE_H_
 
 #include <stddef.h>
 #include <time.h>
 
@@ skipping 62 matching lines @@
   struct Entry {
     Entry();
     Entry(Entry&&);
     ~Entry();
 
     int lookups;
     bssl::UniquePtr<SSL_SESSION> session;
   };
 
   // base::MemoryCoordinatorClient implementation:
-  void OnMemoryStateChange(base::MemoryState state) override;
+  void OnPurgeMemory() override;
 
   // Returns true if |entry| is expired as of |now|.
   bool IsExpired(SSL_SESSION* session, time_t now);
 
   // Removes all expired sessions from the cache.
   void FlushExpiredSessions();
 
   // Clear cache on low memory notifications callback.
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
   std::unique_ptr<base::Clock> clock_;
   Config config_;
   base::HashingMRUCache<std::string, Entry> cache_;
   size_t lookups_since_flush_;
 
   // TODO(davidben): After https://crbug.com/458365 is fixed, replace this with
   // a ThreadChecker. The session cache should be single-threaded like other
   // classes in net.
   base::Lock lock_;
 
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(SSLClientSessionCache);
 };
 
 }  // namespace net
 
 #endif  // NET_SSL_SSL_CLIENT_SESSION_CACHE_H_