--- a/mobile/android/base/java/org/mozilla/gecko/text/FloatingToolbarTextSelection.java
+++ b/mobile/android/base/java/org/mozilla/gecko/text/FloatingToolbarTextSelection.java
@@ -28,22 +28,22 @@ import ch.boye.httpclientandroidlib.util
 
 /**
  * Floating toolbar for text selection actions. Only on Android 6+.
  */
 @TargetApi(Build.VERSION_CODES.M)
 public class FloatingToolbarTextSelection implements TextSelection, GeckoEventListener {
     private static final String LOGTAG = "GeckoFloatTextSelection";
 
-    private Activity activity;
+    private final Activity activity;
+    private final LayerView layerView;
+    private final int[] locationInWindow;
+
     private ActionMode actionMode;
     private FloatingActionModeCallback actionModeCallback;
-    private LayerView layerView;
-    private int[] locationInWindow;
-
     private String selectionID;
     /* package-private */ Rect contentRect;
 
     public FloatingToolbarTextSelection(Activity activity, LayerView layerView) {
         this.activity = activity;
         this.layerView = layerView;
         this.locationInWindow = new int[2];
     }