Send notification to users upon receiving sms messages

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index fd9f1d430615dd7f577083db9de80fbe4d7376f5..85cbab9084f040a95139e11933f0925f97a1c785 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -247,12 +247,12 @@ component("ash") {
     "common/system/chromeos/network/network_portal_detector_observer.h",
     "common/system/chromeos/network/network_state_list_detailed_view.cc",
     "common/system/chromeos/network/network_state_list_detailed_view.h",
+    "common/system/chromeos/network/sms_observer.cc",
+    "common/system/chromeos/network/sms_observer.h",
     "common/system/chromeos/network/tray_network.cc",
     "common/system/chromeos/network/tray_network.h",
     "common/system/chromeos/network/tray_network_state_observer.cc",
     "common/system/chromeos/network/tray_network_state_observer.h",
-    "common/system/chromeos/network/tray_sms.cc",
-    "common/system/chromeos/network/tray_sms.h",
     "common/system/chromeos/network/tray_vpn.cc",
     "common/system/chromeos/network/tray_vpn.h",
     "common/system/chromeos/network/vpn_list.cc",
@@ -1182,6 +1182,7 @@ test("ash_unittests") {
     # TODO: convert to use AshTest http://crbug.com/654495.
     "common/system/chromeos/ime_menu/ime_menu_tray_unittest.cc",
     "common/system/chromeos/media_security/multi_profile_media_tray_item_unittest.cc",
+    "common/system/chromeos/network/sms_observer_unittest.cc",
     "common/system/chromeos/palette/mock_palette_tool_delegate.cc",
     "common/system/chromeos/palette/mock_palette_tool_delegate.h",
     "common/system/chromeos/palette/palette_tool_manager_unittest.cc",