diff --git a/chrome/browser/ui/tabs/tab_strip_model_observer.h b/chrome/browser/ui/tabs/tab_strip_model_observer.h
index 8dacb579e..495e31bc5 100644
--- a/chrome/browser/ui/tabs/tab_strip_model_observer.h
+++ b/chrome/browser/ui/tabs/tab_strip_model_observer.h
@@ -125,7 +125,7 @@ class TabStripModelChange {
 
  private:
   const Type type_ = kSelectionOnly;
-  const std::vector<Delta> deltas_;
+  const std::vector<Delta> deltas_ = {};
 
   DISALLOW_COPY_AND_ASSIGN(TabStripModelChange);
 };