[USS] Change the place where SharedModelTypeProcessor got created

components/sync_driver/non_blocking_data_type_controller.cc

Index: components/sync_driver/non_blocking_data_type_controller.cc
diff --git a/components/sync_driver/non_blocking_data_type_controller.cc b/components/sync_driver/non_blocking_data_type_controller.cc
index f2996ab1e97325dfd0b5577de28efb704b36a651..5271a6fa6923c771c89941e1fa9baacdff44b4b1 100644
--- a/components/sync_driver/non_blocking_data_type_controller.cc
+++ b/components/sync_driver/non_blocking_data_type_controller.cc
@@ -12,6 +12,8 @@
 #include "base/single_thread_task_runner.h"
 #include "components/sync_driver/backend_data_type_configurer.h"
 #include "components/sync_driver/sync_client.h"
+#include "sync/api/model_type_change_processor.h"
+#include "sync/api/model_type_service.h"
 #include "sync/api/sync_error.h"
 #include "sync/api/sync_merge_result.h"
 #include "sync/internal_api/public/activation_context.h"
@@ -53,11 +55,8 @@ void NonBlockingDataTypeController::LoadModels(
   // Start the type processor on the model thread.
   if (!RunOnModelThread(
           FROM_HERE,
-          base::Bind(
-              &syncer_v2::SharedModelTypeProcessor::OnSyncStarting,
-              type_processor(),
-              base::Bind(&NonBlockingDataTypeController::OnProcessorStarted,
-                         this)))) {
+          base::Bind(&NonBlockingDataTypeController::LoadModelsOnModelThread,
+                     this))) {
     LoadModelsDone(
         UNRECOVERABLE_ERROR,
         syncer::SyncError(FROM_HERE, syncer::SyncError::DATATYPE_ERROR,
@@ -65,6 +64,11 @@ void NonBlockingDataTypeController::LoadModels(
   }
 }
 
+void NonBlockingDataTypeController::LoadModelsOnModelThread() {
+  type_processor()->OnSyncStarting(
+      base::Bind(&NonBlockingDataTypeController::OnProcessorStarted, this));
+}
+
 void NonBlockingDataTypeController::LoadModelsDone(
     ConfigureResult result,
     const syncer::SyncError& error) {
@@ -150,8 +154,11 @@ void NonBlockingDataTypeController::Stop() {
 
   RunOnModelThread(
       FROM_HERE,
-      base::Bind(&syncer_v2::SharedModelTypeProcessor::DisconnectSync,
-                 type_processor()));
+      base::Bind(&NonBlockingDataTypeController::StopOnModelThread, this));
+}
+
+void NonBlockingDataTypeController::StopOnModelThread() {

[maxbogue, 2016/03/15 17:37:33]

Why did you switch to having this extra function instead of binding
DisconnectSync directly?

[Gang Wu, 2016/03/22 00:33:39]

Doing this because my previous patch, change it back. 

+  type_processor()->DisconnectSync();
 }
 
 std::string NonBlockingDataTypeController::name() const {
@@ -232,12 +239,12 @@ void NonBlockingDataTypeController::InitializeProcessorOnModelThread() {
     // set an error state to |state_|.
   }
 
-  scoped_ptr<syncer_v2::SharedModelTypeProcessor> shared_model_type_processor(
-      make_scoped_ptr(new syncer_v2::SharedModelTypeProcessor(
-          type(), model_type_service.get())));
-  type_processor_ = shared_model_type_processor->AsWeakPtrForUI();
-  model_type_service->set_change_processor(
-      std::move(shared_model_type_processor));
+  syncer_v2::ModelTypeChangeProcessor* processor =
+      model_type_service->InitializeProcessor(base::Bind(

[maxbogue, 2016/03/15 17:37:33]

As we discussed at the very end of the meeting, this function should simply get
cast the return value of ModelTypeService::OnSyncStarting().

[Gang Wu, 2016/03/22 00:33:39]

Done.

+          &NonBlockingDataTypeController::CreateSharedModelTypeProcessor,
+          this));
+  DCHECK(processor);
+  DCHECK_EQ(type_processor_.get(), processor);
 }
 
 void NonBlockingDataTypeController::InitializeProcessor() {
@@ -249,4 +256,16 @@ void NonBlockingDataTypeController::InitializeProcessor() {
           this));
 }
 
+scoped_ptr<syncer_v2::ModelTypeChangeProcessor>
+NonBlockingDataTypeController::CreateSharedModelTypeProcessor(

[maxbogue, 2016/03/15 17:37:33]

This shouldn't be in the DTC. It needs to be passed into the constructor of the
service.

[Gang Wu, 2016/03/22 00:33:39]

Done.

+    syncer_v2::ModelTypeService* service) {
+  DCHECK(!type_processor_.get());
+  scoped_ptr<syncer_v2::SharedModelTypeProcessor> shared_model_type_processor(
+      make_scoped_ptr(
+          new syncer_v2::SharedModelTypeProcessor(type(), service)));
+  type_processor_ = shared_model_type_processor->AsWeakPtrForUI();
+  return make_scoped_ptr<syncer_v2::ModelTypeChangeProcessor>(
+      shared_model_type_processor.release());
+}
+
 }  // namespace sync_driver_v2