Reload wallpaper when display configuration changes.

ash/test/test_user_wallpaper_delegate.h

Index: ash/test/test_user_wallpaper_delegate.h
diff --git a/ash/test/test_user_wallpaper_delegate.h b/ash/test/test_user_wallpaper_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..56842357d75a85cff869c4aaa08bebd8a72aae7a
--- /dev/null
+++ b/ash/test/test_user_wallpaper_delegate.h
@@ -0,0 +1,32 @@
+// Copyright 2013 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_TEST_TEST_USER_WALLPAPER_DELEGATE_H_
+#define ASH_TEST_TEST_USER_WALLPAPER_DELEGATE_H_
+
+#include "ash/default_user_wallpaper_delegate.h"
+
+namespace ash {
+namespace test {
+
+class TestUserWallpaperDelegate : public DefaultUserWallpaperDelegate {
+ public:
+  TestUserWallpaperDelegate() : update_wallpaper_count_(0) {}
+  virtual ~TestUserWallpaperDelegate() {}
+
+  // DefaultUserWallpaperDelegate overrides:
+  virtual void UpdateWallpaper() OVERRIDE;
+
+  int GetUpdateWallpaperCountAndReset();
+
+ private:
+  int update_wallpaper_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestUserWallpaperDelegate);
+};
+
+}  // namespace test
+}  // namespace ash
+
+#endif  // ASH_TEST_TEST_USER_WALLPAPER_DELEGATE_H_