Revert "Modify Autotest API to support views based lockscreen"

This reverts commit 7df02c0d.

Reason for revert: Failed desktopui_ScreenLocker autotest

Original change's description:
> Modify Autotest API to support views based lockscreen
> 
> Bug: 781998
> Change-Id: I11a456b1341d044b1370652c337f105e0bef649a
> Reviewed-on: https://chromium-review.googlesource.com/803622
> Commit-Queue: Xiaoyin Hu <xiaoyinh@chromium.org>
> Reviewed-by: Jacob Dufault <jdufault@chromium.org>
> Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#521137}

TBR=achuith@chromium.org,jdufault@chromium.org,xiaoyinh@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 781998
Change-Id: I547a15a15d2cf3b95986e8cfbf548b95cd0b3087
Reviewed-on: https://chromium-review.googlesource.com/812264Reviewed-by: Xiaoyin Hu <xiaoyinh@chromium.org>
Commit-Queue: Xiaoyin Hu <xiaoyinh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522225}

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

@@ -109,7 +109,6 @@ class ScreenLocker : public AuthStatusConsumer,
   // Returns the default instance if it has been created.
   static ScreenLocker* default_screen_locker() { return screen_locker_; }
 
-  // Returns true if the lock UI has been confirmed as displayed.
   bool locked() const { return locked_; }
 
   // Initialize and show the screen locker.

chrome/browser/extensions/api/autotest_private/autotest_private_api.cc

@@ -109,12 +109,8 @@ ExtensionFunction::ResponseAction AutotestPrivateLoginStatusFunction::Run() {
 #if defined(OS_CHROMEOS)
   const user_manager::UserManager* user_manager =
       user_manager::UserManager::Get();
-
-  // default_screen_locker()->locked() is set when the UI is ready, so this
-  // tells us both views based lockscreen UI and screenlocker are ready.
   const bool is_screen_locked =
-      !!chromeos::ScreenLocker::default_screen_locker() &&
-      chromeos::ScreenLocker::default_screen_locker()->locked();
+      !!chromeos::ScreenLocker::default_screen_locker();
 
   if (user_manager) {
     result->SetBoolean("isLoggedIn", user_manager->IsUserLoggedIn());