[Sync] Notify the datatype of the current context on startup

In order to support context triggered refreshes, the datatype must know
what the current context is at startup to decide whether a refresh must
be performed or not. We will now invoke UpdateDataTypeContext before
MergeDataAndStartSyncing if a valid context exists.

BUG=357368
R=rlarocque@chromium.org

Review URL: https://codereview.chromium.org/233833003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263376 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 75 insertions, 2 deletions

diff --git a/chrome/browser/sync/glue/fake_generic_change_processor.cc b/chrome/browser/sync/glue/fake_generic_change_processor.cc
index f068dc6..0e1eeb9 100644
--- a/chrome/browser/sync/glue/fake_generic_change_processor.cc
+++ b/chrome/browser/sync/glue/fake_generic_change_processor.cc
@@ -55,6 +55,12 @@ syncer::SyncError FakeGenericChangeProcessor::GetAllSyncDataReturnError(
   return get_sync_data_for_type_error_;
 }
 
+bool FakeGenericChangeProcessor::GetDataTypeContext(
+    syncer::ModelType type,
+    std::string* context) const {
+  return false;
+}
+
 int FakeGenericChangeProcessor::GetSyncCountForType(syncer::ModelType type) {
   return 0;
 }
diff --git a/chrome/browser/sync/glue/fake_generic_change_processor.h b/chrome/browser/sync/glue/fake_generic_change_processor.h
index bf493dc..489af73 100644
--- a/chrome/browser/sync/glue/fake_generic_change_processor.h
+++ b/chrome/browser/sync/glue/fake_generic_change_processor.h
@@ -31,6 +31,8 @@ class FakeGenericChangeProcessor : public GenericChangeProcessor {
   virtual syncer::SyncError GetAllSyncDataReturnError(
       syncer::ModelType type,
       syncer::SyncDataList* data) const OVERRIDE;
+  virtual bool GetDataTypeContext(syncer::ModelType type,
+                                  std::string* context) const OVERRIDE;
   virtual int GetSyncCountForType(syncer::ModelType type) OVERRIDE;
   virtual bool SyncModelHasUserCreatedNodes(syncer::ModelType type,
                                             bool* has_nodes) OVERRIDE;
diff --git a/chrome/browser/sync/glue/generic_change_processor.cc b/chrome/browser/sync/glue/generic_change_processor.cc
index 0505f4f..18382aa 100644
--- a/chrome/browser/sync/glue/generic_change_processor.cc
+++ b/chrome/browser/sync/glue/generic_change_processor.cc
@@ -233,6 +233,21 @@ syncer::SyncError GenericChangeProcessor::GetAllSyncDataReturnError(
   return syncer::SyncError();
 }
 
+bool GenericChangeProcessor::GetDataTypeContext(syncer::ModelType type,
+                                                std::string* context) const {
+  syncer::ReadTransaction trans(FROM_HERE, share_handle());
+  sync_pb::DataTypeContext context_proto;
+  trans.GetDataTypeContext(type, &context_proto);
+  if (!context_proto.has_context())
+    return false;
+
+  DCHECK_EQ(type,
+            syncer::GetModelTypeFromSpecificsFieldNumber(
+                context_proto.data_type_id()));
+  *context = context_proto.context();
+  return true;
+}
+
 int GenericChangeProcessor::GetSyncCountForType(syncer::ModelType type) {
   syncer::ReadTransaction trans(FROM_HERE, share_handle());
   syncer::ReadNode root(&trans);
diff --git a/chrome/browser/sync/glue/generic_change_processor.h b/chrome/browser/sync/glue/generic_change_processor.h
index cbed785..2af4e4e 100644
--- a/chrome/browser/sync/glue/generic_change_processor.h
+++ b/chrome/browser/sync/glue/generic_change_processor.h
@@ -79,6 +79,12 @@ class GenericChangeProcessor : public ChangeProcessor,
       syncer::ModelType type,
       syncer::SyncDataList* data) const;
 
+  // If a datatype context associated with |type| exists, fills |context| and
+  // returns true. Otheriwse, if there has not been a context set, returns
+  // false.
+  virtual bool GetDataTypeContext(syncer::ModelType type,
+                                  std::string* context) const;
+
   // Returns the number of items for this type.
   virtual int GetSyncCountForType(syncer::ModelType type);
 
diff --git a/chrome/browser/sync/glue/non_ui_data_type_controller.cc b/chrome/browser/sync/glue/non_ui_data_type_controller.cc
index 83c7dd7..ba47bcf 100644
--- a/chrome/browser/sync/glue/non_ui_data_type_controller.cc
+++ b/chrome/browser/sync/glue/non_ui_data_type_controller.cc
@@ -379,6 +379,12 @@ void NonUIDataTypeController::
     return;
   }
 
+  std::string datatype_context;
+  if (shared_change_processor_->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|.
diff --git a/chrome/browser/sync/glue/shared_change_processor.cc b/chrome/browser/sync/glue/shared_change_processor.cc
index f3f6fd6..f4393e2 100644
--- a/chrome/browser/sync/glue/shared_change_processor.cc
+++ b/chrome/browser/sync/glue/shared_change_processor.cc
@@ -183,6 +183,17 @@ bool SharedChangeProcessor::CryptoReadyIfNecessary() {
   return generic_change_processor_->CryptoReadyIfNecessary(type_);
 }
 
+bool SharedChangeProcessor::GetDataTypeContext(std::string* context) const {
+  DCHECK(backend_loop_.get());
+  DCHECK(backend_loop_->BelongsToCurrentThread());
+  AutoLock lock(monitor_lock_);
+  if (disconnected_) {
+    LOG(ERROR) << "Change processor disconnected.";
+    return false;
+  }
+  return generic_change_processor_->GetDataTypeContext(type_, context);
+}
+
 void SharedChangeProcessor::ActivateDataType(
     syncer::ModelSafeGroup model_safe_group) {
   DCHECK(backend_loop_.get());
diff --git a/chrome/browser/sync/glue/shared_change_processor.h b/chrome/browser/sync/glue/shared_change_processor.h
index eff7dc2..1012676 100644
--- a/chrome/browser/sync/glue/shared_change_processor.h
+++ b/chrome/browser/sync/glue/shared_change_processor.h
@@ -94,6 +94,11 @@ class SharedChangeProcessor
   virtual bool SyncModelHasUserCreatedNodes(bool* has_nodes);
   virtual bool CryptoReadyIfNecessary();
 
+  // If a datatype context associated with the current type exists, fills
+  // |context| and returns true. Otheriwse, if there has not been a context
+  // set, returns false.
+  virtual bool GetDataTypeContext(std::string* context) const;
+
   // Register |generic_change_processor_| as the change processor for the
   // current type on |model_safe_group|.
   // Does nothing if |disconnected_| is true.
diff --git a/chrome/browser/sync/glue/shared_change_processor_mock.h b/chrome/browser/sync/glue/shared_change_processor_mock.h
index 0335125..21a3f5a 100644
--- a/chrome/browser/sync/glue/shared_change_processor_mock.h
+++ b/chrome/browser/sync/glue/shared_change_processor_mock.h
@@ -34,6 +34,7 @@ class SharedChangeProcessorMock : public SharedChangeProcessor {
   MOCK_METHOD1(SyncModelHasUserCreatedNodes,
                bool(bool*));
   MOCK_METHOD0(CryptoReadyIfNecessary, bool());
+  MOCK_CONST_METHOD1(GetDataTypeContext, bool(std::string*));
   MOCK_METHOD1(ActivateDataType,
                void(syncer::ModelSafeGroup));
 
diff --git a/chrome/browser/sync/glue/ui_data_type_controller.cc b/chrome/browser/sync/glue/ui_data_type_controller.cc
index 884c73b..bbd840a 100644
--- a/chrome/browser/sync/glue/ui_data_type_controller.cc
+++ b/chrome/browser/sync/glue/ui_data_type_controller.cc
@@ -182,6 +182,12 @@ void UIDataTypeController::Associate() {
     return;
   }
 
+  std::string datatype_context;
+  if (shared_change_processor_->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_|.
diff --git a/sync/internal_api/public/read_transaction.h b/sync/internal_api/public/read_transaction.h
index 02e2633..3a3dc8d 100644
--- a/sync/internal_api/public/read_transaction.h
+++ b/sync/internal_api/public/read_transaction.h
@@ -13,6 +13,10 @@ namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects
 
+namespace sync_pb {
+class DataTypeContext;
+}
+
 namespace syncer {
 
 struct UserShare;
@@ -35,7 +39,11 @@ class SYNC_EXPORT ReadTransaction : public BaseTransaction {
 
   // Return |transaction_version| of |type| stored in sync directory's
   // persisted info.
-  int64 GetModelVersion(ModelType type);
+  int64 GetModelVersion(ModelType type) const;
+
+  // Fills |context| with the datatype context associated with |type|.
+  void GetDataTypeContext(ModelType type,
+                          sync_pb::DataTypeContext* context) const;
 
  private:
   void* operator new(size_t size);  // Transaction is meant for stack use only.
diff --git a/sync/internal_api/read_transaction.cc b/sync/internal_api/read_transaction.cc
index 81e5340..ebc56ec 100644
--- a/sync/internal_api/read_transaction.cc
+++ b/sync/internal_api/read_transaction.cc
@@ -36,8 +36,15 @@ syncable::BaseTransaction* ReadTransaction::GetWrappedTrans() const {
   return transaction_;
 }
 
-int64 ReadTransaction::GetModelVersion(ModelType type) {
+int64 ReadTransaction::GetModelVersion(ModelType type) const {
   return transaction_->directory()->GetTransactionVersion(type);
 }
 
+void ReadTransaction::GetDataTypeContext(
+    ModelType type,
+    sync_pb::DataTypeContext* context) const {
+  return transaction_->directory()->GetDataTypeContext(
+      transaction_, type, context);
+}
+
 }  // namespace syncer