title: CoordinatorLayout leaves empty space at the bottom after scrolling
body: <p>I am trying to implement Google's newest design tricks with CoordinatorLayout and have problems with scrolling and parallax effect. </p>
  
  <p>After Activity is displayed, everything looks ok but the problem occurs when I try to scroll. It seems the bottom View is not expanded correctly and after it's scrolled up, empty space appears below. Bottom View seems to be big only how much it has on initial display between top View and nav bar.</p>
  
  <p>It looks something like this:</p>
  
  <p><a href="https://i.stack.imgur.com/ntAcE.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/ntAcE.jpg" alt="enter image description here"></a></p>
  
  <p>Relevant code:</p>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;
  
  &lt;CoordinatorLayout
      android:layout_height="match_parent"
      android:layout_width="match_parent"&gt;
  
      &lt;AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"&gt;
  
          &lt;CollapsingToolbarLayout
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              app:layout_scrollFlags="scroll|exitUntilCollapsed"
              app:expandedTitleMarginStart="72dp"
              app:expandedTitleMarginEnd="16dp"&gt;
  
              &lt;ImageView
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  app:layout_collapseMode="parallax"/&gt;
          &lt;/CollapsingToolbarLayout&gt;
      &lt;/AppBarLayout&gt;
  
      &lt;ViewPager
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:layout_behavior="@string/appbar_scrolling_view_behavior"/&gt;
  
  &lt;/CoordinatorLayout&gt;
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p>This weird behavior happens randomly. Sometimes bottom View is scrollable normally and that empty space doesn't appear. What am I doing wrong? Thanks.</p>