Change event routers from singletons to being owned by the ExtensionService.

chrome/browser/extensions/extension_cookies_api.cc

Index: chrome/browser/extensions/extension_cookies_api.cc
diff --git a/chrome/browser/extensions/extension_cookies_api.cc b/chrome/browser/extensions/extension_cookies_api.cc
index 83c535db7c6e5e2f117f585fd4e0037a51475194..bce7fbdb4400983b162fc38702ccb931980825a1 100644
--- a/chrome/browser/extensions/extension_cookies_api.cc
+++ b/chrome/browser/extensions/extension_cookies_api.cc
@@ -25,11 +25,6 @@
 
 namespace keys = extension_cookies_api_constants;
 
-// static
-ExtensionCookiesEventRouter* ExtensionCookiesEventRouter::GetInstance() {
-  return Singleton<ExtensionCookiesEventRouter>::get();
-}
-
 void ExtensionCookiesEventRouter::Init() {
   if (registrar_.IsEmpty()) {
     registrar_.Add(this,