Let ModelTypeService create SharedModelTypeProcessor instead

of ModelTypeController.
Only change the place where to create, still need to figure
out where to trigger.

BUG=547087

Review URL: https://codereview.chromium.org/1763953002

Cr-Commit-Position: refs/heads/master@{#383357}

3 files changed, 55 insertions, 11 deletions

diff --git a/sync/api/model_type_change_processor.h b/sync/api/model_type_change_processor.h
index 5578db7..91f7380 100644
--- a/sync/api/model_type_change_processor.h
+++ b/sync/api/model_type_change_processor.h
@@ -10,6 +10,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "sync/api/entity_data.h"
 #include "sync/base/sync_export.h"
+#include "sync/internal_api/public/activation_context.h"
 
 namespace syncer {
 class SyncError;
@@ -24,6 +25,9 @@ class MetadataChangeList;
 // changes.
 class SYNC_EXPORT ModelTypeChangeProcessor {
  public:
+  typedef base::Callback<void(syncer::SyncError, scoped_ptr<ActivationContext>)>
+      StartCallback;
+
   ModelTypeChangeProcessor();
   virtual ~ModelTypeChangeProcessor();
 
@@ -42,6 +46,12 @@ class SYNC_EXPORT ModelTypeChangeProcessor {
   // Accept the initial sync metadata loaded by the service. This should be
   // called as soon as the metadata is available to the service.
   virtual void OnMetadataLoaded(scoped_ptr<MetadataBatch> batch) = 0;
+
+  // Called by the DataTypeController to gather additional information needed
+  // before a CommitQueue object can be created for this model type. Once the
+  // metadata has been loaded, the info is collected and given to |callback|.
+  // Once called, this can only be called again if sync is disconnected.
+  virtual void OnSyncStarting(const StartCallback& callback) = 0;
 };
 
 }  // namespace syncer_v2
diff --git a/sync/api/model_type_service.cc b/sync/api/model_type_service.cc
index 87df14b..a8c7933 100644
--- a/sync/api/model_type_service.cc
+++ b/sync/api/model_type_service.cc
@@ -4,9 +4,14 @@
 
 #include "sync/api/model_type_service.h"
 
+#include "sync/api/model_type_change_processor.h"
+
 namespace syncer_v2 {
 
-ModelTypeService::ModelTypeService() {}
+ModelTypeService::ModelTypeService(
+    const ChangeProcessorFactory& change_processor_factory,
+    syncer::ModelType type)
+    : change_processor_factory_(change_processor_factory), type_(type) {}
 
 ModelTypeService::~ModelTypeService() {}
 
@@ -14,15 +19,29 @@ ModelTypeChangeProcessor* ModelTypeService::change_processor() const {
   return change_processor_.get();
 }
 
-void ModelTypeService::set_change_processor(
-    scoped_ptr<ModelTypeChangeProcessor> change_processor) {
-  DCHECK(!change_processor_);
-  change_processor_.swap(change_processor);
-  OnChangeProcessorSet();
+ModelTypeChangeProcessor* ModelTypeService::GetOrCreateChangeProcessor() {
+  if (!change_processor_) {
+    change_processor_ = change_processor_factory_.Run(type(), this);
+    DCHECK(change_processor_);
+    OnChangeProcessorSet();
+  }
+  return change_processor_.get();
 }
 
 void ModelTypeService::clear_change_processor() {
   change_processor_.reset();
 }
 
+ModelTypeChangeProcessor* ModelTypeService::OnSyncStarting(
+    const ModelTypeChangeProcessor::StartCallback& start_callback) {
+  ModelTypeChangeProcessor* processor = GetOrCreateChangeProcessor();
+  DCHECK(processor);
+  processor->OnSyncStarting(start_callback);
+  return processor;
+}
+
+syncer::ModelType ModelTypeService::type() const {
+  return type_;
+}
+
 }  // namespace syncer_v2
diff --git a/sync/api/model_type_service.h b/sync/api/model_type_service.h
index bba4211..59579ad 100644
--- a/sync/api/model_type_service.h
+++ b/sync/api/model_type_service.h
@@ -15,6 +15,7 @@
 #include "sync/api/model_type_change_processor.h"
 #include "sync/api/sync_error.h"
 #include "sync/base/sync_export.h"
+#include "sync/internal_api/public/activation_context.h"
 
 namespace syncer_v2 {
 
@@ -29,8 +30,13 @@ class SYNC_EXPORT ModelTypeService {
   typedef base::Callback<void(syncer::SyncError, scoped_ptr<DataBatch>)>
       DataCallback;
   typedef std::vector<std::string> ClientTagList;
+  typedef base::Callback<scoped_ptr<ModelTypeChangeProcessor>(
+      syncer::ModelType,
+      ModelTypeService* service)>
+      ChangeProcessorFactory;
 
-  ModelTypeService();
+  ModelTypeService(const ChangeProcessorFactory& change_processor_factory,
+                   syncer::ModelType type);
 
   virtual ~ModelTypeService();
 
@@ -78,17 +84,26 @@ class SYNC_EXPORT ModelTypeService {
   // it to the processor.
   virtual void OnChangeProcessorSet() = 0;
 
+  void clear_change_processor();
+
+  ModelTypeChangeProcessor* OnSyncStarting(
+      const ModelTypeChangeProcessor::StartCallback& callback);
+
+ protected:
   // TODO(skym): See crbug/547087, do we need all these accessors?
   ModelTypeChangeProcessor* change_processor() const;
 
-  void set_change_processor(
-      scoped_ptr<ModelTypeChangeProcessor> change_processor);
+  ModelTypeChangeProcessor* GetOrCreateChangeProcessor();
 
-  void clear_change_processor();
+  // Model type for this service.
+  syncer::ModelType type() const;
 
  private:
-  // Recieves ownership in set_change_processor(...).
   scoped_ptr<ModelTypeChangeProcessor> change_processor_;
+
+  ChangeProcessorFactory change_processor_factory_;
+
+  const syncer::ModelType type_;
 };
 
 }  // namespace syncer_v2