Use mirror layer for minimized windows in overview mode

ash/common/wm/overview/window_selector_item.h

Index: ash/common/wm/overview/window_selector_item.h
diff --git a/ash/common/wm/overview/window_selector_item.h b/ash/common/wm/overview/window_selector_item.h
index ce5f171de58830edad92809dfa4abda4edcd9504..f2ff9df8daaa78ed89787173f532a76f33c6699f 100644
--- a/ash/common/wm/overview/window_selector_item.h
+++ b/ash/common/wm/overview/window_selector_item.h
@@ -97,10 +97,6 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Restores stacking of window captions above the windows, then fades out.
   void Shutdown();
 
-  // Forces the managed window to be shown (ie not hidden or minimized) when
-  // calling RestoreWindow().
-  void ShowWindowOnExit();
-
   // Dispatched before beginning window overview. This will do any necessary
   // one time actions such as restoring minimized windows.
   void PrepareForOverview();
@@ -138,6 +134,9 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Hides the original window header.
   void HideHeader();
 
+  // Called when the window is minimized or unminimized.
+  void OnMinimizedStateChanged();
+
   // Sets if the item is dimmed in the overview. Changing the value will also
   // change the visibility of the transform windows.
   void SetDimmed(bool dimmed);
@@ -200,6 +199,8 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Allows a test to directly set animation state.
   gfx::SlideAnimation* GetBackgroundViewAnimation();
 
+  WmWindow* GetOverviewWindowForMinimizedStateForTest();
+
   // True if the item is being shown in the overview, false if it's being
   // filtered.
   bool dimmed_;