Abstract pref storage from net::SdchOwner

ios/crnet/crnet_environment.mm

Index: ios/crnet/crnet_environment.mm
diff --git a/ios/crnet/crnet_environment.mm b/ios/crnet/crnet_environment.mm
index 0118dd731d40cf8e4cbf32063cdb72cbd82e0cf6..670acc0eb9f1996d60bf1c47ec692451affdb734 100644
--- a/ios/crnet/crnet_environment.mm
+++ b/ios/crnet/crnet_environment.mm
@@ -26,6 +26,7 @@
 #include "base/threading/worker_pool.h"
 #import "components/webp_transcode/webp_network_client_factory.h"
 #include "crypto/nss_util.h"
+#include "ios/crnet/sdch_owner_pref_storage.h"
 #include "ios/net/cookies/cookie_store_ios.h"
 #include "ios/net/crn_http_protocol_handler.h"
 #include "ios/net/empty_nsurlcache.h"
@@ -338,7 +339,10 @@ void CrNetEnvironment::ConfigureSdchOnNetworkThread() {
   }
 
   sdch_manager_.reset(new net::SdchManager());
-  sdch_owner_.reset(new net::SdchOwner(sdch_manager_.get(), context));
+  sdch_owner_.reset(
+      new net::SdchOwner(scoped_ptr<net::SdchOwner::PrefStorage>(
+                             new SdchOwnerPrefStorage(sdch_manager_.get())),
+                         context));
   if (!sdch_pref_store_filename_.empty()) {
     base::FilePath path(sdch_pref_store_filename_);
     pref_store_worker_pool_ = file_user_blocking_thread_->task_runner();