cros: WallpaperController reparent based on session state

chrome/browser/chromeos/login/lock/screen_locker.cc

Index: chrome/browser/chromeos/login/lock/screen_locker.cc
diff --git a/chrome/browser/chromeos/login/lock/screen_locker.cc b/chrome/browser/chromeos/login/lock/screen_locker.cc
index e67e5992a6f7c325766a0ab88f369a6a5f62cee8..42a3399b6d0c18367e68a34b7a46861738efeea3 100644
--- a/chrome/browser/chromeos/login/lock/screen_locker.cc
+++ b/chrome/browser/chromeos/login/lock/screen_locker.cc
@@ -8,7 +8,6 @@
 #include <vector>
 
 #include "ash/shell.h"
-#include "ash/wallpaper/wallpaper_controller.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_state_aura.h"
 #include "ash/wm/window_util.h"
@@ -510,9 +509,6 @@ ScreenLocker::~ScreenLocker() {
     authenticator_->SetConsumer(NULL);
   ClearErrors();
 
-  VLOG(1) << "Moving wallpaper to unlocked container";
-  ash::Shell::Get()->wallpaper_controller()->MoveToUnlockedContainer();

[xiyuan, 2017/04/21 15:30:58]

Covered by session state change to ACTIVE in line 528.

-
   screen_locker_ = NULL;
   bool state = false;
   VLOG(1) << "Emitting SCREEN_LOCK_STATE_CHANGED with state=" << state;
@@ -544,9 +540,6 @@ void ScreenLocker::ScreenLockReady() {
           << delta.InSecondsF() << " second(s)";
   UMA_HISTOGRAM_TIMES("ScreenLocker.ScreenLockTime", delta);
 
-  VLOG(1) << "Moving wallpaper to locked container";
-  ash::Shell::Get()->wallpaper_controller()->MoveToLockedContainer();

[xiyuan, 2017/04/21 15:30:58]

Covered by session state change to LOCKED in line 559.

-
   bool state = true;
   VLOG(1) << "Emitting SCREEN_LOCK_STATE_CHANGED with state=" << state;
   content::NotificationService::current()->Notify(