[Cronet] Enable persistence mode for Sdch

components/cronet/android/cronet_url_request_context_adapter.h

 // Copyright 2014 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 COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_
 #define COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_
 
 #include <jni.h>
 
 #include <queue>
 #include <string>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/prefs/json_pref_store.h"
 #include "base/threading/thread.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace net {
 class WriteToFileNetLogObserver;
 class URLRequestContext;
 class ProxyConfigService;
@@ skipping 54 matching lines @@
 
   scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner() const;
 
   void StartNetLogToFileOnNetworkThread(const std::string& file_name,
                                         bool log_all);
 
   void StopNetLogOnNetworkThread();
 
   // Network thread is owned by |this|, but is destroyed from java thread.
   base::Thread* network_thread_;
+  scoped_ptr<base::Thread> file_thread_;
   // |write_to_file_observer_| and |context_| should only be accessed on
   // network thread.
   scoped_ptr<net::WriteToFileNetLogObserver> write_to_file_observer_;
   scoped_ptr<net::URLRequestContext> context_;
   scoped_ptr<net::ProxyConfigService> proxy_config_service_;
+  scoped_refptr<JsonPrefStore> network_json_store_;
   scoped_ptr<net::SdchOwner> sdch_owner_;

[mef, 2015/05/13 15:15:22]

Should we add a comment that sdch_owner_ must be destroyed before pref store?

[mmenke, 2015/05/13 15:34:41]

PrefStore is refcounted (shudder), so that's actually not the case.

We may need to destroy both of them before the file thread, though I'm not sure
of that.

[mef, 2015/05/13 15:50:09]

Umm, but as long as we hold the ref to PrefStore while destroying the sdch owner
it should be the case, right?
The PrefStore takes task_runner, which is refcounted and can outlive the thread,
but I guess if file thread is destroyed, then that could miss some latest writes
to prefstore before it is destroyed.

[xunjieli, 2015/05/13 16:57:44]

Done. Added comment about the order.

 
   // Context config is only valid untng context is initialized.
   scoped_ptr<URLRequestContextConfig> context_config_;
 
   // A queue of tasks that need to be run after context has been initialized.
   std::queue<base::Closure> tasks_waiting_for_context_;
   bool is_context_initialized_;
   int default_load_flags_;
 
   DISALLOW_COPY_AND_ASSIGN(CronetURLRequestContextAdapter);
 };
 
 }  // namespace cronet
 
 #endif  // COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_