Restore tray background when locking screen.

ash/wm/shelf_layout_manager.h

 // 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.
 
 #ifndef ASH_WM_SHELF_LAYOUT_MANAGER_H_
 #define ASH_WM_SHELF_LAYOUT_MANAGER_H_
 #pragma once
 
 #include "ash/ash_export.h"
 #include "ash/launcher/launcher.h"
@@ skipping 132 matching lines @@
   struct TargetBounds {
     TargetBounds() : opacity(0.0f) {}
 
     float opacity;
     gfx::Rect launcher_bounds;
     gfx::Rect status_bounds;
     gfx::Insets work_area_insets;
   };
 
   struct State {
-    State() : visibility_state(VISIBLE), auto_hide_state(AUTO_HIDE_HIDDEN) {}
+    State() : visibility_state(VISIBLE),
+              auto_hide_state(AUTO_HIDE_HIDDEN),
+              is_screen_locked(false) {}
 
     // Returns true if the two states are considered equal. As
     // |auto_hide_state| only matters if |visibility_state| is |AUTO_HIDE|,
     // Equals() ignores the |auto_hide_state| as appropriate.
     bool Equals(const State& other) const {
       return other.visibility_state == visibility_state &&
           (visibility_state != AUTO_HIDE ||
-           other.auto_hide_state == auto_hide_state);
+           other.auto_hide_state == auto_hide_state) &&
+          other.is_screen_locked == is_screen_locked;
     }
 
     VisibilityState visibility_state;
     AutoHideState auto_hide_state;
+    bool is_screen_locked;
   };
 
   // Sets the visibility of the shelf to |state|.
   void SetState(VisibilityState visibility_state);
 
   // Stops any animations.
   void StopAnimating();
 
   // Calculates the target bounds assuming visibility of |visible|.
   void CalculateTargetBounds(const State& state,
@@ skipping 47 matching lines @@
   // trigger showing the launcher.
   scoped_ptr<AutoHideEventFilter> event_filter_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfLayoutManager);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_SHELF_LAYOUT_MANAGER_H_