mash: Migrate wallpaper controllers to ash/common.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 7bbbf4e580b6357357e4065c5f5c0c40f1926f16..fb27bcbbae69c05d5f7326826d8a57aa1761ef13 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -58,8 +58,6 @@
 #include "ash/shell_init_params.h"
 #include "ash/system/chromeos/screen_layout_observer.h"
 #include "ash/utility/screenshot_controller.h"
-#include "ash/wallpaper/wallpaper_controller.h"
-#include "ash/wallpaper/wallpaper_view.h"
 #include "ash/wm/ash_focus_rules.h"
 #include "ash/wm/ash_native_cursor_manager.h"
 #include "ash/wm/event_client_impl.h"
@@ -627,7 +625,6 @@ Shell::~Shell() {
 #if defined(OS_CHROMEOS)
   resolution_notification_controller_.reset();
 #endif
-  wallpaper_controller_.reset();
   screenshot_controller_.reset();
   mouse_cursor_filter_.reset();
   modality_filter_.reset();
@@ -888,9 +885,6 @@ void Shell::Init(const ShellInitParams& init_params) {
 
   event_client_.reset(new EventClientImpl);
 
-  // This controller needs to be set before SetupManagedWindowMode.
-  wallpaper_controller_.reset(new WallpaperController(blocking_pool_));
-
   session_state_delegate_.reset(
       wm_shell_->delegate()->CreateSessionStateDelegate());
   wm_shell_->CreatePointerWatcherAdapter();