Implement a RenderFrame-less path for Web Notifications.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 8f7f539b7af78f025c8d5cb4147d1e4b08ab3d32..2b646222aa4357b80f7b39b5a698fbe1c3aeac63 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -71,6 +71,7 @@
 #include "content/browser/message_port_message_filter.h"
 #include "content/browser/mime_registry_message_filter.h"
 #include "content/browser/mojo/mojo_application_host.h"
+#include "content/browser/notification_message_filter.h"
 #include "content/browser/profiler_message_filter.h"
 #include "content/browser/push_messaging_message_filter.h"
 #include "content/browser/quota_dispatcher_host.h"
@@ -847,6 +848,9 @@ void RenderProcessHostImpl::CreateMessageFilters() {
       GetID(),
       storage_partition_impl_->GetQuotaManager(),
       GetContentClient()->browser()->CreateQuotaPermissionContext()));
+  AddFilter(new NotificationMessageFilter(
+      GetID(),
+      resource_context));
   AddFilter(new GamepadBrowserMessageFilter());
   AddFilter(new DeviceLightMessageFilter());
   AddFilter(new DeviceMotionMessageFilter());