(Merge to M-51) Revise the shelf alignment locking mechanism.

ash/shelf/shelf_layout_manager.h

 // Copyright 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_SHELF_SHELF_LAYOUT_MANAGER_H_
 #define ASH_SHELF_SHELF_LAYOUT_MANAGER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 173 matching lines @@
     shelf_->shelf()->SetAlignment(alignment);
   }
   ShelfAlignment GetAlignment() const { return shelf_->GetAlignment(); }
 
   // TODO(harrym|oshima): These templates will be moved to a new Shelf class.
   // A helper function for choosing values specific to a shelf alignment.
   template <typename T>
   T SelectValueForShelfAlignment(T bottom, T left, T right) const {
     switch (GetAlignment()) {
       case SHELF_ALIGNMENT_BOTTOM:
+      case SHELF_ALIGNMENT_BOTTOM_LOCKED:
         return bottom;
       case SHELF_ALIGNMENT_LEFT:
         return left;
       case SHELF_ALIGNMENT_RIGHT:
         return right;
     }
     NOTREACHED();
     return right;
   }
 
   template<typename T>
   T PrimaryAxisValue(T horizontal, T vertical) const {
     return IsHorizontalAlignment() ? horizontal : vertical;
   }
 
   // Is the shelf's alignment horizontal?
   bool IsHorizontalAlignment() const;
 
-  // Returns true when the alignment is locked. This can be caused by the screen
-  // being locked, or when adding a user. Returns false when transitioning to a
-  // user session, and while the session is active.
-  bool IsAlignmentLocked() const;
-
   // Set the height of the ChromeVox panel, which takes away space from the
   // available work area from the top of the screen.
   void SetChromeVoxPanelHeight(int height);
 
  private:
   class AutoHideEventFilter;
   class UpdateShelfObserver;
   friend class AshPopupAlignmentDelegateTest;
   friend class ash::ScreenAsh;
   friend class PanelLayoutManagerTest;
@@ skipping 173 matching lines @@
 
   // The show hide animation duration override or 0 for default.
   int duration_override_in_ms_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfLayoutManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_LAYOUT_MANAGER_H_