Only clip PopupWindow in the vertical direction

Bug: 29865091
Change-Id: Ic4e3b50571034f341aff2c2fbf2c349342622448
diff --git a/core/java/android/widget/PopupWindow.java b/core/java/android/widget/PopupWindow.java
index 6477f07..6432f70 100644
--- a/core/java/android/widget/PopupWindow.java
+++ b/core/java/android/widget/PopupWindow.java
@@ -1396,7 +1396,7 @@
     private int computeGravity() {
         int gravity = Gravity.START | Gravity.TOP;
         if (mClipToScreen || mClippingEnabled) {
-            gravity |= Gravity.DISPLAY_CLIP_VERTICAL | Gravity.DISPLAY_CLIP_HORIZONTAL;
+            gravity |= Gravity.DISPLAY_CLIP_VERTICAL;
         }
         return gravity;
     }