Add SessionStateObserver with ActiveUserChanged()

ash/shelf/shelf_layout_manager_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/shelf/shelf_layout_manager.h"
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_table.h"
 #include "ash/ash_switches.h"
 #include "ash/display/display_manager.h"
@@ skipping 1228 matching lines @@
   shelf->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_NEVER);
   EXPECT_FALSE(tray->HasSystemBubble());
 
   // Now, drag up on the tray to show the bubble.
   gfx::Point start = GetShelfWidget()->status_area_widget()->
       GetWindowBoundsInScreen().CenterPoint();
   gfx::Point end(start.x(), start.y() - 100);
   generator.GestureScrollSequence(start, end,
       base::TimeDelta::FromMilliseconds(10), 1);
   EXPECT_TRUE(tray->HasSystemBubble());
-  tray->CloseSystemBubbleForTest();
+  tray->CloseSystemBubble();
   RunAllPendingInMessageLoop();
   EXPECT_FALSE(tray->HasSystemBubble());
 
   // Drag again, but only a small amount, and slowly. The bubble should not be
   // visible.
   end.set_y(start.y() - 30);
   generator.GestureScrollSequence(start, end,
       base::TimeDelta::FromMilliseconds(500), 100);
   EXPECT_FALSE(tray->HasSystemBubble());
 
@@ skipping 146 matching lines @@
     // allow auto hide.
     shelf->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_NEVER);
     EXPECT_FALSE(status_area_widget->IsMessageBubbleShown());
     gfx::Point center =
         status_area_widget->GetWindowBoundsInScreen().CenterPoint();
     generator.MoveMouseTo(center.x(), center.y());
     shelf->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS);
     EXPECT_TRUE(shelf->IsVisible());
     if (!i) {
       // In our first iteration we make sure there is no bubble.
-      tray->CloseSystemBubbleForTest();
+      tray->CloseSystemBubble();
       EXPECT_FALSE(status_area_widget->IsMessageBubbleShown());
     } else {
       // In our second iteration we show a bubble.
       TestItem *item = new TestItem;
       tray->AddTrayItem(item);
       tray->ShowNotificationView(item);
       EXPECT_TRUE(status_area_widget->IsMessageBubbleShown());
     }
     // Move the pointer over the edge of the shelf.
     generator.MoveMouseTo(
         center.x(), status_area_widget->GetWindowBoundsInScreen().y() - 8);
     shelf->UpdateVisibilityState();
     if (i) {
       EXPECT_TRUE(shelf->IsVisible());
       EXPECT_TRUE(status_area_widget->IsMessageBubbleShown());
     } else {
       EXPECT_FALSE(shelf->IsVisible());
       EXPECT_FALSE(status_area_widget->IsMessageBubbleShown());
     }
   }
 }
 
 }  // namespace internal
 }  // namespace ash