Revert ActivityManager changes for tasks. DO NOT MERGE

Keeping all activity=>task changes in master and removing them
from jb-mr2.

Revert "Update histories simultaneously."
Revert "Add null check to setAppGroupId."
Revert "Fix crashing bug in validator."
Revert "Switch topRunning* and moveTaskTo*"
Revert "Begin switch over to task based history."
Revert "Reset and reuse Iterators and don't new() one."
Revert "Remove AppWindowToken lists."
Revert "Fix build."
Revert "Remove unused App methods."
Revert "Stop using AppToken movement and start using Task."
Revert "Replace access to mAppTokens with AppTokenIterator"
Revert "Refactor setAppOpVisibility implementation."
Revert "Add AppWindowTokens to TaskList."
Revert "Make ActivityStack.mHistory private."
Revert "Migrate AppWindowToken lists into DisplayContent."

Change-Id: I5722c9a4956dccb52864207e2967690bc58e4ebb
diff --git a/services/java/com/android/server/wm/WindowState.java b/services/java/com/android/server/wm/WindowState.java
index 517c4e4..a600623 100644
--- a/services/java/com/android/server/wm/WindowState.java
+++ b/services/java/com/android/server/wm/WindowState.java
@@ -52,12 +52,6 @@
 import java.util.ArrayList;
 
 class WindowList extends ArrayList<WindowState> {
-    WindowList() {
-        super();
-    }
-    WindowList(WindowList windows) {
-        super(windows);
-    }
 }
 
 /**
@@ -1092,7 +1086,7 @@
         return true;
     }
 
-    public void setAppOpVisibilityLw(boolean state) {
+    public boolean setAppOpVisibilityLw(boolean state) {
         if (mAppOpVisibility != state) {
             mAppOpVisibility = state;
             if (state) {
@@ -1102,11 +1096,13 @@
                 // ops modifies they should only be hidden by policy due to the
                 // lock screen, and the user won't be changing this if locked.
                 // Plus it will quickly be fixed the next time we do a layout.
-                showLw(true, true);
+                showLw(true, false);
             } else {
-                hideLw(true, true);
+                hideLw(true, false);
             }
+            return true;
         }
+        return false;
     }
 
     @Override