android: add to DisplayPortMetrics position and zoom getter

Change-Id: I90674f51113c082d3bd88a72f8b9883b44569f87

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/DisplayPortMetrics.java

@@ -20,6 +20,14 @@ public final class DisplayPortMetrics {
     private final RectF mPosition;
     private final float mResolution;
 
+    public RectF getPosition() {
+        return mPosition;
+    }
+
+    public float getResolution() {
+        return mResolution;
+    }
+
     public DisplayPortMetrics() {
         this(0, 0, 0, 0, 1);
     }