Move the content-dependent RecreateLayer logic from aura::Window to RWHVA

ash/display/mirror_window_controller.cc

Index: ash/display/mirror_window_controller.cc
diff --git a/ash/display/mirror_window_controller.cc b/ash/display/mirror_window_controller.cc
index 32d38749ec62309cacda330b105709503a96a2e7..1a338fec766960c1be6706bc3841889af1dbe6d0 100644
--- a/ash/display/mirror_window_controller.cc
+++ b/ash/display/mirror_window_controller.cc
@@ -116,10 +116,8 @@ class CursorWindowDelegate : public aura::WindowDelegate {
     return false;
   }
   virtual void GetHitTestMask(gfx::Path* mask) const OVERRIDE {}
-  virtual scoped_refptr<ui::Texture> CopyTexture() OVERRIDE {
-    NOTREACHED();
-    return scoped_refptr<ui::Texture>();
-  }
+  virtual void DidRecreateLayer(ui::Layer* old_layer,
+                                ui::Layer* new_layer) OVERRIDE {}
 
   // Set the cursor image for the |display|'s scale factor.  Note that
   // mirror window's scale factor is always 1.0f, therefore we need to