[Merge to M58]Chrome OS: revert the device wallpaper change within a user session.

components/wallpaper/wallpaper_manager_base.h

Index: components/wallpaper/wallpaper_manager_base.h
diff --git a/components/wallpaper/wallpaper_manager_base.h b/components/wallpaper/wallpaper_manager_base.h
index 4e9aed774fff869c475f355ee096a07486d4a15a..3c31f52bf5a9cd8747c07ef05c11e9ef2aed1c1e 100644
--- a/components/wallpaper/wallpaper_manager_base.h
+++ b/components/wallpaper/wallpaper_manager_base.h
@@ -354,12 +354,8 @@ class WALLPAPER_EXPORT WallpaperManagerBase {
   // Ruturns files identifier for the |account_id|.
   virtual WallpaperFilesId GetFilesId(const AccountId& account_id) const = 0;
 
-  // If the device is enterprise managed and we're at the login screen, set the
-  // device wallpaper as the login screen wallpaper. If the device is enterprise
-  // managed and we're in a user session, only set the device wallpaper if there
-  // is no user policy wallpaper and the user hasn't changed the default or the
-  // device wallpaper. Returns true if the device wallpaper should be set as the
-  // wallpaper, otherwise returns false.
+  // If the device is enterprise managed and the device wallpaper policy exists,
+  // set the device wallpaper as the login screen wallpaper.
   virtual bool SetDeviceWallpaperIfApplicable(const AccountId& account_id) = 0;
 
  protected: