Fix issue #2191572: Difficulties drawing window shade

The touch location filtering hacks had a little problem.

Change-Id: Ib57366169c87f83af1adcc8b6a00dadc01582339
diff --git a/services/java/com/android/server/InputDevice.java b/services/java/com/android/server/InputDevice.java
index eaad3b7..6eb6242 100644
--- a/services/java/com/android/server/InputDevice.java
+++ b/services/java/com/android/server/InputDevice.java
@@ -65,6 +65,7 @@
         
         // This is the last generated pointer data, ordered to match
         // mPointerIds.
+        boolean mSkipLastPointers;
         int mLastNumPointers = 0;
         final int[] mLastData = new int[MotionEvent.NUM_SAMPLE_DATA * MAX_POINTERS];
         
@@ -511,6 +512,11 @@
                 long curTimeNano, Display display, int orientation,
                 int metaState) {
             
+            if (mSkipLastPointers) {
+                mSkipLastPointers = false;
+                mLastNumPointers = 0;
+            }
+            
             if (mNextNumPointers <= 0 && mLastNumPointers <= 0) {
                 return null;
             }