Move all wallpaper file loading and decoding from DesktopBackgroundController to WallpaperManager.

ash/desktop_background/desktop_background_controller_test_api.cc

Index: ash/desktop_background/desktop_background_controller_test_api.cc
diff --git a/ash/desktop_background/desktop_background_controller_test_api.cc b/ash/desktop_background/desktop_background_controller_test_api.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5bb7c0d426f2b58e789fab38af84d3d59e4e044f
--- /dev/null
+++ b/ash/desktop_background/desktop_background_controller_test_api.cc
@@ -0,0 +1,19 @@
+// 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.
+
+#include "ash/desktop_background/desktop_background_controller_test_api.h"
+
+namespace ash {
+
+DesktopBackgroundController::TestAPI::TestAPI(
+    DesktopBackgroundController* controller)
+    : controller_(controller) {
+}
+
+void DesktopBackgroundController::TestAPI::set_wallpaper_reload_delay_for_test(
+    bool value) {
+  controller_->set_wallpaper_reload_delay_for_test(value);
+}
+
+}  // namespace ash