[Sync] Post back to UI thread for USS GetAllNodes.

components/sync/driver/model_type_controller.cc

Index: components/sync/driver/model_type_controller.cc
diff --git a/components/sync/driver/model_type_controller.cc b/components/sync/driver/model_type_controller.cc
index 5b4329f178abcf6fc46fdb9002586c0512aa3881..8e98059415eaecb64f5cac21c0e69bfda79a9217 100644
--- a/components/sync/driver/model_type_controller.cc
+++ b/components/sync/driver/model_type_controller.cc
@@ -226,8 +226,8 @@ DataTypeController::State ModelTypeController::state() const {
 }
 
 void ModelTypeController::GetAllNodes(const AllNodesCallback& callback) {
-  PostBridgeTask(FROM_HERE,
-                 base::Bind(&ModelTypeDebugInfo::GetAllNodes, callback));
+  PostBridgeTask(FROM_HERE, base::Bind(&ModelTypeDebugInfo::GetAllNodes,
+                                       BindToCurrentThread(callback)));
 }
 
 void ModelTypeController::GetStatusCounters(