Have SimpleCache index listen to android activity status notifications.

net/disk_cache/simple/simple_index.h

 // Copyright (c) 2013 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_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_
 
 #include <list>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/activity_status.h"
+#endif
+
 class Pickle;
 class PickleIterator;
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace disk_cache {
 
 class NET_EXPORT_PRIVATE EntryMetadata {
@@ skipping 111 matching lines @@
       const base::FilePath& index_filename);
 
   static void WriteToDiskInternal(const base::FilePath& index_filename,
                                   scoped_ptr<Pickle> pickle,
                                   const base::TimeTicks& start_time);
 
   // Must run on IO Thread.
   void MergeInitializingSet(scoped_ptr<EntrySet> index_file_entries,
                             bool force_index_flush);
 
+#if defined(OS_ANDROID)
+  void OnActivityStateChange(base::android::ActivityState state);
+
+  scoped_ptr<base::android::ActivityStatus::Listener> activity_status_listener_;
+#endif
+
   EntrySet entries_set_;
+
   uint64 cache_size_;  // Total cache storage size in bytes.
   uint64 max_size_;
   uint64 high_watermark_;
   uint64 low_watermark_;
   bool eviction_in_progress_;
   base::TimeTicks eviction_start_time_;
 
   // This stores all the hash_key of entries that are removed during
   // initialization.
   base::hash_set<uint64> removed_entries_;
   bool initialized_;
 
   base::FilePath index_filename_;
 
   scoped_refptr<base::SingleThreadTaskRunner> cache_thread_;
   scoped_refptr<base::SingleThreadTaskRunner> io_thread_;
 
   // All nonstatic SimpleEntryImpl methods should always be called on the IO
   // thread, in all cases. |io_thread_checker_| documents and enforces this.
   base::ThreadChecker io_thread_checker_;
 
   // Timestamp of the last time we wrote the index to disk.
   // PostponeWritingToDisk() may give up postponing and allow the write if it
   // has been a while since last time we wrote.
   base::Time last_write_to_disk_;
   base::OneShotTimer<SimpleIndex> write_to_disk_timer_;
 
   typedef std::list<net::CompletionCallback> CallbackList;
   CallbackList to_run_when_initialized_;
+
+  // Set to true when the app is on the background. When the app is in the
+  // background we can write the index much more frequently, to insure fresh
+  // index on next startup.
+  bool app_on_background_;
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_