[Cronet] Enable persistence mode for Sdch

components/cronet/android/cronet_url_request_context_adapter.h

Index: components/cronet/android/cronet_url_request_context_adapter.h
diff --git a/components/cronet/android/cronet_url_request_context_adapter.h b/components/cronet/android/cronet_url_request_context_adapter.h
index a1f64c28e0b22a0a1a61c3883400ccc4ef0ff4db..490953c6119e35ad1c8857b4022945ae8db5ef73 100644
--- a/components/cronet/android/cronet_url_request_context_adapter.h
+++ b/components/cronet/android/cronet_url_request_context_adapter.h
@@ -15,6 +15,7 @@
 #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 {
@@ -89,11 +90,13 @@ class CronetURLRequestContextAdapter {
 
   // 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.