diff --git a/extensions/browser/mock_extension_system.cc b/extensions/browser/mock_extension_system.cc
index 8371c95..845ab9e 100644
--- a/extensions/browser/mock_extension_system.cc
+++ b/extensions/browser/mock_extension_system.cc
@@ -9,7 +9,7 @@
 namespace extensions {
 
 MockExtensionSystem::MockExtensionSystem(content::BrowserContext* context)
-    : browser_context_(context), event_router_(nullptr) {
+    : browser_context_(context) {
 }
 
 MockExtensionSystem::~MockExtensionSystem() {
@@ -46,10 +46,6 @@
   return nullptr;
 }
 
-EventRouter* MockExtensionSystem::event_router() {
-  return event_router_;
-}
-
 QuotaService* MockExtensionSystem::quota_service() {
   return nullptr;
 }