<RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom">
            <android.support.design.widget.FloatingActionButton
                android:id="@+id/fab"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentRight="true"
                android:layout_above="@+id/ad_view"
                android:layout_margin="@dimen/fab_margin"
                android:src="@android:drawable/ic_dialog_email" />

            <com.google.android.gms.ads.AdView
                android:id="@+id/ad_view"
                android:layout_width="match_parent"
                android:layout_height="50dp"
                android:layout_alignParentBottom="true"
                app:adSize="FULL_WIDTHx50"
                app:adUnitId="@string/banner_ad_unit_id" />

        </RelativeLayout>