Revert "Fix problems with KeyguardManager.exitKeyguardSecurely() and the FLAG_SHOW_WHEN_LOCKED window manager flag."

We have a better solution for this in the Phone app.
This reverts commit b684251e8f1e85ea9483af2b80bc92f0fd8ded1c.
diff --git a/policy/com/android/internal/policy/impl/KeyguardViewMediator.java b/policy/com/android/internal/policy/impl/KeyguardViewMediator.java
index 17586be..6b9db60 100644
--- a/policy/com/android/internal/policy/impl/KeyguardViewMediator.java
+++ b/policy/com/android/internal/policy/impl/KeyguardViewMediator.java
@@ -170,7 +170,7 @@
     // these are protected by synchronized (this)
 
     /**
-     * This is set to false if the keyguard is disabled via setKeyguardEnabled(false).
+     * External apps (like the phone app) can tell us to disable the keygaurd.
      */
     private boolean mExternallyEnabled = true;
 
@@ -398,31 +398,15 @@
                 // don't allow this api when the device isn't provisioned
                 if (DEBUG) Log.d(TAG, "ignoring because device isn't provisioned");
                 callback.onKeyguardExitResult(false);
+            } else if (mExternallyEnabled) {
+                // this only applies when the user has externally disabled the
+                // keyguard.  this is unexpected and means the user is not
+                // using the api properly.
+                Log.w(TAG, "verifyUnlock called when not externally disabled");
+                callback.onKeyguardExitResult(false);
             } else if (mExitSecureCallback != null) {
                 // already in progress with someone else
                 callback.onKeyguardExitResult(false);
-            } else if (mExternallyEnabled) {
-                if (mHidden) {
-                    if (isSecure()) {
-                        // if the current activity is in front of the keyguard, then
-                        // pretend like we succeeded and we will hit the lock screen
-                        // when the activity is launched.
-                        // HACK ALERT - this is assuming that the callback will be used
-                        // to start a new activity (current usage by Phone app).
-                        callback.onKeyguardExitResult(true);
-                    } else {
-                        // call through to verifyUnlockLocked() so we can bypass
-                        // the insecure keyguard screen.
-                        mExitSecureCallback = callback;
-                        verifyUnlockLocked();
-                    }
-                } else {
-                    // this only applies when the user has externally disabled the keyguard
-                    // and no other activities are in front of the keyguard.
-                    // this is unexpected and means the user is not using the api properly.
-                    Log.w(TAG, "verifyUnlock called when not externally disabled");
-                    callback.onKeyguardExitResult(false);
-                }
             } else {
                 mExitSecureCallback = callback;
                 verifyUnlockLocked();