Add the basic code skeleton for system info event router

chrome/browser/extensions/event_names.cc

Index: chrome/browser/extensions/event_names.cc
diff --git a/chrome/browser/extensions/event_names.cc b/chrome/browser/extensions/event_names.cc
index 93d4b84c0218567cea895fff5339ad4915501a83..2b23876004a3f87df8aa9218a5d31527eeb53353 100644
--- a/chrome/browser/extensions/event_names.cc
+++ b/chrome/browser/extensions/event_names.cc
@@ -70,6 +70,11 @@ const char kBluetoothOnPowerChanged[] =
 
 const char kOnPushMessage[] = "experimental.pushMessaging.onMessage";
 
+const char kOnStorageAvailableCapacityChanged[] =
+     "experimental.systemInfo.storage.onAvailableCapacityChanged";
+const char kOnStorageAdded[] = "experimental.systemInfo.storage.onAdded";
+const char kOnStorageRemoved[] = "experimental.systemInfo.storage.onRemoved";
+
 }  // namespace event_names
 
 }  // namespace extensions