WorkspaceLayoutManager backdrop should fill entire region.

ash/wm/maximize_mode/workspace_backdrop_delegate.h

 // Copyright 2014 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_MAXIMIZE_MODE_WORKSPACE_BACKDROP_DELEGATE_H_
 #define ASH_WM_MAXIMIZE_MODE_WORKSPACE_BACKDROP_DELEGATE_H_
 
 #include "ash/wm/workspace/workspace_layout_manager_delegate.h"
 #include "ui/aura/window_observer.h"
 
@@ skipping 27 matching lines @@
 
   // WorkspaceLayoutManagerDelegate overrides:
   virtual void OnWindowAddedToLayout(aura::Window* child) OVERRIDE;
   virtual void OnWindowRemovedFromLayout(aura::Window* child) OVERRIDE;
   virtual void OnChildWindowVisibilityChanged(aura::Window* child,
                                               bool visible) OVERRIDE;
   virtual void OnWindowStackingChanged(aura::Window* window) OVERRIDE;
   virtual void OnPostWindowStateTypeChange(
       wm::WindowState* window_state,
       wm::WindowStateType old_type) OVERRIDE;
+  virtual void OnDisplayWorkAreaInsetsChanged() OVERRIDE;
 
  private:
   // Restack the backdrop relatively to the other windows in the container.
   void RestackBackdrop();
 
   // Returns the current visible top level window in the container.
   aura::Window* GetCurrentTopWindow();
 
   // Position & size the background over the container window.
   void AdjustToContainerBounds();
 
   // Show the overlay.
   void Show();
 
   // The background which covers the rest of the screen.
   views::Widget* background_;
 
   // The window which is being "maximized".
   aura::Window* container_;
 
   // If true, the |RestackOrHideWindow| might recurse.
   bool in_restacking_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkspaceBackdropDelegate);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_MAXIMIZE_MODE_WORKSPACE_BACKDROP_DELEGATE_H_