Converts MruWindowTracker to work with common types

ash/common/wm_shell.h

 // Copyright 2016 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_COMMON_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 54 matching lines @@
   virtual std::vector<WmWindow*> GetMruWindowListIgnoreModals() = 0;
 
   // Returns true if the first window shown on first run should be
   // unconditionally maximized, overriding the heuristic that normally chooses
   // the window size.
   virtual bool IsForceMaximizeOnFirstRun() = 0;
 
   virtual bool IsUserSessionBlocked() = 0;
   virtual bool IsScreenLocked() = 0;
 
+  // Returns true if |window| can be shown for the current user. This is
+  // intended to check if the current users matches the user associated with

[James Cook, 2016/06/07 01:21:04]

nit: "current users" -> "current user" (unless this is somehow dealing with
multiprofile/multiuser, which I'm guessing not).

[sky, 2016/06/07 02:46:21]

Done.

+  // |window|.
+  virtual bool CanShowWindowForUser(WmWindow* window) = 0;
+
   // See aura::client::CursorClient for details on these.
   virtual void LockCursor() = 0;
   virtual void UnlockCursor() = 0;
 
   virtual std::vector<WmWindow*> GetAllRootWindows() = 0;
 
   virtual void RecordUserMetricsAction(wm::WmUserMetricsAction action) = 0;
 
   // Returns a WindowResizer to handle dragging. |next_window_resizer| is
   // the next WindowResizer in the WindowResizer chain. This may return
@@ skipping 16 matching lines @@
   virtual void AddOverviewModeObserver(WmOverviewModeObserver* observer) = 0;
   virtual void RemoveOverviewModeObserver(WmOverviewModeObserver* observer) = 0;
 
  private:
   static WmShell* instance_;
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_