title: ViewPager in CoordinatorLayout then scroll tablayout offscreen not working
body: <p>I have a viewpager in CoordinatorLayout like this:</p>
  
  <pre><code>    &lt;android.support.design.widget.AppBarLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"&gt;
  
      &lt;android.support.v7.widget.Toolbar
          android:id="@+id/toolbar"
          android:layout_width="match_parent"
          android:layout_height="?attr/actionBarSize"
          android:background="?attr/colorPrimary"
          app:layout_scrollFlags="scroll|enterAlways"
          app:popupTheme="@style/AppTheme"/&gt;
  
      &lt;android.support.design.widget.TabLayout
          android:id="@+id/tab_layout"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:tabMode="scrollable"/&gt;
  &lt;/android.support.design.widget.AppBarLayout&gt;
  
  &lt;android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      app:layout_behavior="@string/appbar_scrolling_view_behavior" /&gt;
  </code></pre>
  
  <p></p>
  
  <p>and in viewpager, each fragment is a webview.</p>
  
  <p>The code can be run but when I scroll my webview. the tablayout offscreen not working. it just at the header.</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>I try to use relativelayout to content my views and use NestedScrollView as the relativelayout's parent but the webview disappeared(progressbar showed fine). Is a bug???</p>
  
  <p>here is my fragment layout:</p>
  
  <pre><code>&lt;android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/nestedScrollView"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;
  
  &lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:minHeight="300dp"&gt;
  
      &lt;ProgressBar
          android:id="@+id/pb"
          style="?android:attr/progressBarStyleHorizontal"
          android:layout_width="fill_parent"
          android:layout_height="2dp"
          android:indeterminateOnly="false"
          android:max="100"
          android:progressDrawable="@drawable/progress_bar_states"&gt;&lt;/ProgressBar&gt;
  
      &lt;com.handmark.pulltorefresh.library.PullToRefreshWebView
          android:id="@+id/webview"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_below="@id/pb" /&gt;
  &lt;/RelativeLayout&gt;
  
  &lt;/android.support.v4.widget.NestedScrollView&gt;
  </code></pre>