Do not activate system tray bubble by default

ash/system/web_notification/web_notification_tray_unittest.cc

Index: ash/system/web_notification/web_notification_tray_unittest.cc
diff --git a/ash/system/web_notification/web_notification_tray_unittest.cc b/ash/system/web_notification/web_notification_tray_unittest.cc
index 8c31338007a39374ecdccd44ed62cffa6a3ca7ef..59b221c6e593488d10390eded374c4a5eb4af577 100644
--- a/ash/system/web_notification/web_notification_tray_unittest.cc
+++ b/ash/system/web_notification/web_notification_tray_unittest.cc
@@ -7,6 +7,7 @@
 #include <utility>
 #include <vector>
 
+#include "ash/common/shelf/shelf_layout_manager.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/status_area_widget.h"
@@ -145,6 +146,10 @@ class WebNotificationTrayTest : public test::AshMDTestBase {
         nullptr, kShellWindowId_DefaultContainer, gfx::Rect(1, 2, 3, 4));
   }
 
+  static void UpdateAutoHideStateNow() {
+    GetPrimaryShelf()->shelf_layout_manager()->UpdateAutoHideStateNow();
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(WebNotificationTrayTest);
 };
@@ -362,6 +367,7 @@ TEST_P(WebNotificationTrayTest, PopupAndAutoHideShelf) {
   TestItem* test_item = new TestItem;
   GetSystemTray()->AddTrayItem(test_item);
   GetSystemTray()->ShowDefaultView(BUBBLE_CREATE_NEW);
+  UpdateAutoHideStateNow();
 
   EXPECT_EQ(SHELF_AUTO_HIDE_SHOWN, shelf->GetAutoHideState());
   EXPECT_TRUE(GetTray()->IsPopupVisible());