Add popup window accessors for anchor overlap, gravity, window

Cleans up comments and some code in PopupWindow.

BUG: 18245054
Change-Id: I2111d0c194ee1a39aaa721083041fc139efcf630
diff --git a/core/java/com/android/internal/view/menu/MenuPopupHelper.java b/core/java/com/android/internal/view/menu/MenuPopupHelper.java
index 99bb1ac..2b20b38 100644
--- a/core/java/com/android/internal/view/menu/MenuPopupHelper.java
+++ b/core/java/com/android/internal/view/menu/MenuPopupHelper.java
@@ -118,6 +118,10 @@
         mDropDownGravity = gravity;
     }
 
+    public int getGravity() {
+        return mDropDownGravity;
+    }
+
     public void show() {
         if (!tryShow()) {
             throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
@@ -135,7 +139,7 @@
         mPopup.setAdapter(mAdapter);
         mPopup.setModal(true);
 
-        View anchor = mAnchorView;
+        final View anchor = mAnchorView;
         if (anchor != null) {
             final boolean addGlobalListener = mTreeObserver == null;
             mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest