sync: Inject sync/'s dependency on invalidations

sync/test/trackable_mock_invalidation.cc

Index: sync/test/trackable_mock_invalidation.cc
diff --git a/sync/test/trackable_mock_invalidation.cc b/sync/test/trackable_mock_invalidation.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5d41f9b3b99b8752a7c512c1cc6e5f1c17745c53
--- /dev/null
+++ b/sync/test/trackable_mock_invalidation.cc
@@ -0,0 +1,38 @@
+
+#include "sync/test/trackable_mock_invalidation.h"
+
+#include "sync/test/mock_invalidation_tracker.h"
+
+namespace syncer {
+
+TrackableMockInvalidation::TrackableMockInvalidation(
+    bool is_unknown_version,
+    int64 version,
+    const std::string& payload,
+    MockInvalidationTracker* tracker,
+    int tracking_id)
+    : MockInvalidation(is_unknown_version, version, payload),
+      tracker_(tracker),
+      tracking_id_(tracking_id) {
+}
+
+TrackableMockInvalidation::~TrackableMockInvalidation() {
+}
+
+void TrackableMockInvalidation::Acknowledge() {
+  if (tracker_) {
+    tracker_->Acknowledge(tracking_id_);
+  }
+}
+
+void TrackableMockInvalidation::Drop() {
+  if (tracker_) {
+    tracker_->Drop(tracking_id_);
+  }
+}
+
+int TrackableMockInvalidation::GetTrackingId() {
+  return tracking_id_;
+}
+
+}  // namespace syncer