arc: Show custom notification via notification surface

chrome/browser/chrome_browser_main_extra_parts_exo.cc

Index: chrome/browser/chrome_browser_main_extra_parts_exo.cc
diff --git a/chrome/browser/chrome_browser_main_extra_parts_exo.cc b/chrome/browser/chrome_browser_main_extra_parts_exo.cc
index cdd2a698bc9276ae3e41a99fe93d33e996f12900..42532a713043c0bd9404ba912d9365f62509a8b5 100644
--- a/chrome/browser/chrome_browser_main_extra_parts_exo.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_exo.cc
@@ -18,6 +18,7 @@
 #include "components/exo/display.h"
 #include "components/exo/wayland/server.h"
 #include "content/public/browser/browser_thread.h"
+#include "ui/arc/notification/arc_custom_notification_item.h"
 
 #if defined(USE_GLIB)
 namespace {
@@ -123,10 +124,15 @@ void ChromeBrowserMainExtraPartsExo::PreProfileInit() {
     wayland_server_ = exo::wayland::Server::Create(display_.get());
     wayland_watcher_ =
         base::WrapUnique(new WaylandWatcher(wayland_server_.get()));
+
+    arc::ArcCustomNotificationItem::SetNotificationSurfaceRegistry(
+        display_->notification_surface_registry());

[Nico, 2016/06/21 18:00:29]

Does this do any interesting work? This runs very early here, so this could slow
down startup.

[xiyuan, 2016/06/21 18:03:57]

Nope. It just passes down the registry pointer to the custom notification code
and stores it there for later use.

   }
 }
 
 void ChromeBrowserMainExtraPartsExo::PostMainMessageLoopRun() {
+  arc::ArcCustomNotificationItem::SetNotificationSurfaceRegistry(nullptr);
+
   wayland_watcher_.reset();
   wayland_server_.reset();
 }