Bug 703004 - Fix NPE on touch during startup [r=pcwalton]

Fix a couple of places that transform a point but
don't properly deal with the possible null return
value.

embedding/android/GeckoAppShell.java

@@ -461,6 +461,9 @@ public class GeckoAppShell
                 /* Transform the point to the layer offset. */
                 PointF eventPoint = new PointF(origX, origY);
                 PointF geckoPoint = layerController.convertViewPointToLayerPoint(eventPoint);
+                if (geckoPoint == null) {
+                    return false;
+                }
                 event.setLocation((int)Math.round(geckoPoint.x), (int)Math.round(geckoPoint.y));
 
                 GeckoAppShell.sendEventToGecko(new GeckoEvent(event));

embedding/android/ui/PanZoomController.java

@@ -594,6 +594,9 @@ public class PanZoomController
         try {
             PointF point = new PointF(motionEvent.getX(), motionEvent.getY());
             point = mController.convertViewPointToLayerPoint(point);
+            if (point == null) {
+                return;
+            }
             ret.put("x", (int)Math.round(point.x));
             ret.put("y", (int)Math.round(point.y));
         } catch(Exception ex) {