sync: Add GetAllSyncData to sync/api

chrome/browser/history/typed_url_syncable_service_unittest.cc

Index: chrome/browser/history/typed_url_syncable_service_unittest.cc
diff --git a/chrome/browser/history/typed_url_syncable_service_unittest.cc b/chrome/browser/history/typed_url_syncable_service_unittest.cc
index e1983824387ce5587d68a0315bf323aac6c72c31..d4d64bf87795cf2d329e8026fbbbf9b20ababb92 100644
--- a/chrome/browser/history/typed_url_syncable_service_unittest.cc
+++ b/chrome/browser/history/typed_url_syncable_service_unittest.cc
@@ -48,6 +48,10 @@ class TestChangeProcessor : public syncer::SyncChangeProcessor {
     return syncer::SyncError();
   }
 
+  virtual syncer::SyncDataList GetAllSyncData(syncer::ModelType type) const {
+    return syncer::SyncDataList();
+  }
+
   // Set pointer location to write SyncChanges to in ProcessSyncChanges.
   void SetChangeOutput(syncer::SyncChangeList *change_output) {
     change_output_ = change_output;