Abit/app/src/main/res/layout/toolbar_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
        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"
        android:fitsSystemWindows="true">

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
                 xmlns:tools="http://schemas.android.com/tools"
                 android:layout_below="@id/toolbar"
                 android:id="@+id/content"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 tools:context=".MessageListActivity"
                 tools:layout="@android:layout/list_content"
                 app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        <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="4dp"
                android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:layout_scrollFlags="scroll|enterAlways"/>

    </android.support.design.widget.AppBarLayout>

</android.support.design.widget.CoordinatorLayout>