title: CollapsingToolbarLayout not showing Title
body: <p>In my case, the toolbar disappears when I scroll through the list. I am using a CollapsingToolbarLayout and I need to set the title text. But in my case the title text is not showing, even though I've set it (See code below). What is wrong?</p>
  
  <p><strong>Layout code:</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/drawer_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:fitsSystemWindows="true"&gt;
  
  &lt;android.support.design.widget.CoordinatorLayout
      android:id="@+id/coordinator"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:fitsSystemWindows="true"
          android:theme="@style/AppTheme.AppBarOverlay"
          app:elevation="0dp"&gt;
  
          &lt;android.support.design.widget.CollapsingToolbarLayout
              android:id="@+id/collapsing"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              android:fitsSystemWindows="true"
              app:layout_scrollFlags="scroll|enterAlways"&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"
                  android:elevation="0dp"
                  android:minHeight="?attr/actionBarSize"
                  app:layout_collapseMode="pin"
                  app:popupTheme="@style/AppTheme.PopupOverlay"&gt;
  
              &lt;/android.support.v7.widget.Toolbar&gt;
  
          &lt;/android.support.design.widget.CollapsingToolbarLayout&gt;
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;FrameLayout
          android:id="@+id/content_frame"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:layout_behavior="@string/appbar_scrolling_view_behavior" /&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  
  &lt;android.support.design.widget.NavigationView
      android:id="@+id/nav_view"
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      android:layout_gravity="start"
      app:headerLayout="@layout/app_nav_header_main"
      app:menu="@menu/main_drawer" /&gt;
  
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p><strong>Activity code:</strong></p>
  
  <pre><code> protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.app_activity_with_left_panel);
  
      mPreferences = PreferenceManager.getDefaultSharedPreferences(this);
      mToolbar = (Toolbar) findViewById(R.id.toolbar);
      mCollapsingToolbarLayout = (CollapsingToolbarLayout)findViewById(R.id.collapsing);
      setSupportActionBar(mToolbar);
      setTitle(getIntent().getStringExtra(TITLE));
      getSupportActionBar().setDisplayHomeAsUpEnabled(true);
      getSupportActionBar().setHomeButtonEnabled(true);
  }
  
  @Override
  public void setTitle(CharSequence title) {
      if (title != null &amp;&amp; !title.toString().isEmpty()) {
          mTitle = title.toString();
          mCollapsingToolbarLayout.setTitle(mTitle);
      }
  }
  </code></pre>