Implement WebPushProvider.unregister() in Chromium.

content/browser/push_messaging/push_messaging_message_filter.h

Index: content/browser/push_messaging/push_messaging_message_filter.h
diff --git a/content/browser/push_messaging/push_messaging_message_filter.h b/content/browser/push_messaging/push_messaging_message_filter.h
index 942473968af72e68c9c6b6d52aca4fbf76e1614a..6565f1b4b542138d8acc24f0c0cad0c6089bf6a1 100644
--- a/content/browser/push_messaging/push_messaging_message_filter.h
+++ b/content/browser/push_messaging/push_messaging_message_filter.h
@@ -114,6 +114,19 @@ class PushMessagingMessageFilter : public BrowserMessageFilter {
                                PushRegistrationStatus status,
                                const std::string& push_registration_id);
 
+
+  // Unregister methods --------------------------------------------------------
+
+  void OnUnregister(int request_id,
+                    int64 service_worker_registration_id);
+
+  void UnregisterOnUI(int request_id,
+                      int64 service_worker_registration_id,
+                      const GURL& requesting_origin);
+
+  void DidUnregister(int request_id,
+                     PushUnregistrationStatus unregistration_status);
+
   // Returns a push messaging service. The embedder owns the service, and is
   // responsible for ensuring that it outlives RenderProcessHost. It's valid to
   // return NULL. Must be called on the UI thread.