[Sync] Move StartAssociation from NonUIDataTypeController to SharedChangeProcessor.

components/sync/driver/shared_change_processor.cc

Index: components/sync/driver/shared_change_processor.cc
diff --git a/components/sync/driver/shared_change_processor.cc b/components/sync/driver/shared_change_processor.cc
index 51471c141c18f56cbf0db1c65df63f80acba6015..a7a955a3463b53229e2c82552ae7b3a05efdfba1 100644
--- a/components/sync/driver/shared_change_processor.cc
+++ b/components/sync/driver/shared_change_processor.cc
@@ -4,14 +4,17 @@
 
 #include "components/sync/driver/shared_change_processor.h"
 
+#include <memory>
 #include <utility>
 
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/sync/api/sync_change.h"
 #include "components/sync/api/syncable_service.h"
+#include "components/sync/base/data_type_histogram.h"
 #include "components/sync/core/data_type_error_handler.h"
 #include "components/sync/driver/generic_change_processor.h"
 #include "components/sync/driver/generic_change_processor_factory.h"
+#include "components/sync/driver/shared_change_processor_ref.h"
 #include "components/sync/driver/sync_client.h"
 
 using base::AutoLock;
@@ -22,12 +25,14 @@ class AttachmentService;
 
 namespace sync_driver {
 
-SharedChangeProcessor::SharedChangeProcessor()
+SharedChangeProcessor::SharedChangeProcessor(syncer::ModelType type)
     : disconnected_(false),
-      type_(syncer::UNSPECIFIED),
+      type_(type),
       frontend_task_runner_(base::ThreadTaskRunnerHandle::Get()),
       generic_change_processor_(NULL),
-      error_handler_(NULL) {}
+      error_handler_(NULL) {
+  DCHECK_NE(type_, syncer::UNSPECIFIED);
+}
 
 SharedChangeProcessor::~SharedChangeProcessor() {
   // We can either be deleted when the DTC is destroyed (on UI
@@ -49,24 +54,112 @@ SharedChangeProcessor::~SharedChangeProcessor() {
   }
 }
 
+void SharedChangeProcessor::StartAssociation(
+    StartDoneCallback start_done,
+    SyncClient* const sync_client,
+    syncer::UserShare* user_share,
+    syncer::DataTypeErrorHandler* error_handler) {
+  DCHECK(user_share);
+  syncer::SyncMergeResult local_merge_result(type_);
+  syncer::SyncMergeResult syncer_merge_result(type_);
+  base::WeakPtrFactory<syncer::SyncMergeResult> weak_ptr_factory(
+      &syncer_merge_result);
+
+  // Connect |shared_change_processor| to the syncer and get the
+  // syncer::SyncableService associated with type_.
+  // Note that it's possible the shared_change_processor has already been
+  // disconnected at this point, so all our accesses to the syncer from this
+  // point on are through it.
+  GenericChangeProcessorFactory factory;
+  local_service_ = Connect(sync_client, &factory, user_share, error_handler,
+                           weak_ptr_factory.GetWeakPtr());
+  if (!local_service_.get()) {
+    syncer::SyncError error(FROM_HERE, syncer::SyncError::DATATYPE_ERROR,
+                            "Failed to connect to syncer.", type_);
+    local_merge_result.set_error(error);
+    start_done.Run(DataTypeController::ASSOCIATION_FAILED, local_merge_result,
+                   syncer_merge_result);
+    return;
+  }
+
+  if (!CryptoReadyIfNecessary()) {
+    syncer::SyncError error(FROM_HERE, syncer::SyncError::CRYPTO_ERROR, "",
+                            type_);
+    local_merge_result.set_error(error);
+    start_done.Run(DataTypeController::NEEDS_CRYPTO, local_merge_result,
+                   syncer_merge_result);
+    return;
+  }
+
+  bool sync_has_nodes = false;
+  if (!SyncModelHasUserCreatedNodes(&sync_has_nodes)) {
+    syncer::SyncError error(FROM_HERE, syncer::SyncError::UNRECOVERABLE_ERROR,
+                            "Failed to load sync nodes", type_);
+    local_merge_result.set_error(error);
+    start_done.Run(DataTypeController::UNRECOVERABLE_ERROR, local_merge_result,
+                   syncer_merge_result);
+    return;
+  }
+
+  // Scope for |initial_sync_data| which might be expensive, so we don't want
+  // to keep it in memory longer than necessary.
+  {
+    syncer::SyncDataList initial_sync_data;
+
+    base::TimeTicks start_time = base::TimeTicks::Now();
+    syncer::SyncError error =
+        GetAllSyncDataReturnError(type_, &initial_sync_data);
+    if (error.IsSet()) {
+      local_merge_result.set_error(error);
+      start_done.Run(DataTypeController::ASSOCIATION_FAILED, local_merge_result,
+                     syncer_merge_result);
+      return;
+    }
+
+    std::string datatype_context;
+    if (GetDataTypeContext(&datatype_context)) {
+      local_service_->UpdateDataTypeContext(
+          type_, syncer::SyncChangeProcessor::NO_REFRESH, datatype_context);
+    }
+
+    syncer_merge_result.set_num_items_before_association(
+        initial_sync_data.size());
+    // Passes a reference to |shared_change_processor|.
+    local_merge_result = local_service_->MergeDataAndStartSyncing(
+        type_, initial_sync_data, std::unique_ptr<syncer::SyncChangeProcessor>(
+                                      new SharedChangeProcessorRef(this)),
+        std::unique_ptr<syncer::SyncErrorFactory>(
+            new SharedChangeProcessorRef(this)));
+    RecordAssociationTime(base::TimeTicks::Now() - start_time);
+    if (local_merge_result.error().IsSet()) {
+      start_done.Run(DataTypeController::ASSOCIATION_FAILED, local_merge_result,
+                     syncer_merge_result);
+      return;
+    }
+  }
+
+  syncer_merge_result.set_num_items_after_association(GetSyncCount());
+
+  start_done.Run(!sync_has_nodes ? DataTypeController::OK_FIRST_RUN
+                                 : DataTypeController::OK,
+                 local_merge_result, syncer_merge_result);
+}
+
 base::WeakPtr<syncer::SyncableService> SharedChangeProcessor::Connect(
     SyncClient* sync_client,
     GenericChangeProcessorFactory* processor_factory,
     syncer::UserShare* user_share,
     syncer::DataTypeErrorHandler* error_handler,
-    syncer::ModelType type,
     const base::WeakPtr<syncer::SyncMergeResult>& merge_result) {
   DCHECK(sync_client);
   DCHECK(error_handler);
-  DCHECK_NE(type, syncer::UNSPECIFIED);
   backend_task_runner_ = base::ThreadTaskRunnerHandle::Get();
   AutoLock lock(monitor_lock_);
   if (disconnected_)
     return base::WeakPtr<syncer::SyncableService>();
-  type_ = type;
   error_handler_ = error_handler;
   base::WeakPtr<syncer::SyncableService> local_service =
-      sync_client->GetSyncableServiceForType(type);
+      sync_client->GetSyncableServiceForType(type_);
   if (!local_service.get()) {
     LOG(WARNING) << "SyncableService destroyed before DTC was stopped.";
     disconnected_ = true;
@@ -75,7 +168,7 @@ base::WeakPtr<syncer::SyncableService> SharedChangeProcessor::Connect(
 
   generic_change_processor_ = processor_factory
                                   ->CreateGenericChangeProcessor(
-                                      type, user_share, error_handler,
+                                      type_, user_share, error_handler,
                                       local_service, merge_result, sync_client)
                                   .release();
   // If available, propagate attachment service to the syncable service.
@@ -211,4 +304,17 @@ syncer::SyncError SharedChangeProcessor::CreateAndUploadError(
   }
 }
 
+void SharedChangeProcessor::RecordAssociationTime(base::TimeDelta time) {
+#define PER_DATA_TYPE_MACRO(type_str) \
+  UMA_HISTOGRAM_TIMES("Sync." type_str "AssociationTime", time);
+  SYNC_DATA_TYPE_HISTOGRAM(type_);
+#undef PER_DATA_TYPE_MACRO
+}
+
+void SharedChangeProcessor::StopLocalService() {
+  if (local_service_.get())
+    local_service_->StopSyncing(type_);
+  local_service_.reset();
+}
+
 }  // namespace sync_driver