[Sync] Add favicon sync experiment

sync/internal_api/sync_manager_impl.cc

Index: sync/internal_api/sync_manager_impl.cc
diff --git a/sync/internal_api/sync_manager_impl.cc b/sync/internal_api/sync_manager_impl.cc
index 352a57ead56342d41b9743c9680f26a41bb960b1..bd93a3c2c940c3eee61314bd8598454caa54dcd7 100644
--- a/sync/internal_api/sync_manager_impl.cc
+++ b/sync/internal_api/sync_manager_impl.cc
@@ -1347,10 +1347,6 @@ bool SyncManagerImpl::ReceivedExperiment(Experiments* experiments) {
     return false;
   }
   bool found_experiment = false;
-  if (nigori_node.GetNigoriSpecifics().sync_tab_favicons()) {
-    experiments->sync_tab_favicons = true;
-    found_experiment = true;
-  }
 
   ReadNode keystore_node(&trans);
   if (keystore_node.InitByClientTagLookup(
@@ -1381,6 +1377,15 @@ bool SyncManagerImpl::ReceivedExperiment(Experiments* experiments) {
     found_experiment = true;
   }
 
+  ReadNode favicon_sync_node(&trans);
+  if (favicon_sync_node.InitByClientTagLookup(
+          syncer::EXPERIMENTS,
+          syncer::kFaviconSyncTag) == BaseNode::INIT_OK &&
+      favicon_sync_node.GetExperimentsSpecifics().favicon_sync().enabled()) {
+    experiments->favicon_sync = true;
+    found_experiment = true;
+  }
+
   return found_experiment;
 }