message: set layout handler on button when tab has no name
diff: @@ -152,7 +152,7 @@ const ScrollableTabBar = createReactClass({
  );
  } else {
  return (
  - <Button key={_.random(1.2, 5.2)} onPress={() => onPressHandler(page)}>
  + <Button key={_.random(1.2, 5.2)} onPress={() => onPressHandler(page)} onLayout={onLayoutHandler}>
  <TabHeading scrollable style={tabHeaderStyle} active={isTabActive}>
  {headerContent}
  </TabHeading>
  