Notification actions may have an icon url.

content/public/common/platform_notification_data.h

Index: content/public/common/platform_notification_data.h
diff --git a/content/public/common/platform_notification_data.h b/content/public/common/platform_notification_data.h
index 4a9609ef169c02cdf566acd59cadd54348004cff..3086a769860fb76ebbc72c4483f97c02211f4aaa 100644
--- a/content/public/common/platform_notification_data.h
+++ b/content/public/common/platform_notification_data.h
@@ -26,6 +26,9 @@ struct CONTENT_EXPORT PlatformNotificationAction {
 
   // Title of the button.
   base::string16 title;
+
+  // URL of the icon for the button. May be empty if no url was specified.
+  GURL icon;

[Peter Beverloo, 2016/01/27 13:24:45]

Please make sure that this struct and the IPC_STRUCT_TRAITS in
platform_notification_messages.h stay in sync. Do you want to do serialization
to the database in a separate patch, or add it to this CL? (It should be fairly
trivial.)

[Michael van Ouwerkerk, 2016/01/27 14:24:32]

Done.

 };
 
 // Structure representing the information associated with a Web Notification.