title: Add custom layout to ActionBar/Toolbar with no margins
body: <p>I want to create a custom height toolbar and it works fine until I add content to it. Then my content is adjusted to be between the back arrow and the actionbar buttons. </p>
  
  <p>How can I make my content take the entire width so I can create a layout like below? I guess the "+" icon needs to be in a parent layout of the toolbar? </p>
  
  <p>The docs say: </p>
  
  <blockquote>
    <p>The application may add arbitrary child views to the Toolbar. They will appear at this position within the layout. If a child view's Toolbar.LayoutParams indicates a Gravity value of CENTER_HORIZONTAL the view will attempt to center within the available space remaining in the Toolbar after all other elements have been measured.</p>
  </blockquote>
  
  <p>But I don't have the gravity set to CENTER_HORIZONTAL...
  <img src="https://i.stack.imgur.com/6ay0d.png" alt="Layout I want"></p>
  
  <pre><code> &lt;android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:iosched="http://schemas.android.com/apk/res-auto"
          iosched:theme="@style/ActionBarThemeOverlay"
  
          iosched:popupTheme="@style/ActionBarPopupThemeOverlay"
          android:id="@+id/toolbar_actionbar"
          android:background="@color/theme_primary"
          iosched:titleTextAppearance="@style/ActionBar.TitleText"
          iosched:contentInsetStart="16dp"
          iosched:contentInsetEnd="16dp"
          android:layout_width="match_parent"
          android:layout_height="128dp" &gt;
          &lt;RelativeLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"&gt;
  
          ... My Content
  </code></pre>
  
  <p>Currently my layout ends up like this when running with left margin set to 168: </p>
  
  <p><img src="https://i.stack.imgur.com/Nf2g4.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/6wOrJ.png" alt="layout"></p>