Fix issue #2133206: dialogs/menus should auto-dismiss when screen turns off

Lot of infrastructure for more things to go away when "clear system dialogs"
happens, and now do this when we turn on the lock screen.

Change-Id: I567130296fe47ce82df065ed58ef21b37416ceaf

services/java/com/android/server/WindowManagerService.java

@@ -3913,6 +3913,20 @@ public class WindowManagerService extends IWindowManager.Stub
         return mPolicy.inKeyguardRestrictedKeyInputMode();
     }
 
+    public void closeSystemDialogs(String reason) {
+        synchronized(mWindowMap) {
+            for (int i=mWindows.size()-1; i>=0; i--) {
+                WindowState w = (WindowState)mWindows.get(i);
+                if (w.mSurface != null) {
+                    try {
+                        w.mClient.closeSystemDialogs(reason);
+                    } catch (RemoteException e) {
+                    }
+                }
+            }
+        }
+    }
+    
     static float fixScale(float scale) {
         if (scale < 0) scale = 0;
         else if (scale > 20) scale = 20;