如何同步2个Appbar布局和协调器布局的滚动

Question

活动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:id="@+id/coord"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapse_layout"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        app:layout_scrollFlags="scroll|snap|enterAlwaysCollapsed">


        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="centerCrop"
            android:src="@drawable/material_flat"
            app:layout_collapseMode="parallax" />


        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            style="@style/ToolBarWithNavigationBack"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@android:color/transparent"
            app:layout_collapseMode="pin"></android.support.v7.widget.Toolbar>
    </android.support.design.widget.CollapsingToolbarLayout>

    <LinearLayout
        android:id="@+id/tab_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:background="@android:color/white"
        android:clipToPadding="true"
        android:gravity="center"
        android:orientation="vertical"
        android:paddingTop="10dp"
        app:layout_scrollFlags="scroll|enterAlways|snap">

        <android.support.design.widget.TabLayout
            android:layout_width="fill_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="bottom"
            app:tabIndicatorColor="#BDBDBD"
            app:tabIndicatorHeight="4dp"
            app:tabSelectedTextColor="?android:attr/textColorPrimaryInverse"
            app:tabTextAppearance="@android:style/TextAppearance.Widget.TabWidget" />
    </LinearLayout>

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

<android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

片段xml

    <?xml version="1.0" encoding="utf-8"?>
             <NestedCoordinatorLayout 
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:background="@android:color/background_light">

<android.support.design.widget.AppBarLayout
    android:id="@+id/main.appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:color/white"
    app:theme="@style/ThemeOverlay.AppCompat.Dark">


    <LinearLayout
        android:id="@+id/home"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#e3e6e8"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="20dp"
        app:layout_scrollFlags="scroll|enterAlwaysCollapsed|snap">

        <android.support.v7.widget.CardView
            card_view:cardCornerRadius="4dp"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:layout_margin="24dp">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/shade_gradient" />

        </android.support.v7.widget.CardView>

    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="15dp" />
</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/simple.viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

     </NestedCoordinatorLayout>

当片段中的appbar布局滚动时，活动的appbar布局也应该滚动。

目前当触摸在片段中的视图寻呼机上时，两个appbar都滚动在一起，但当触摸在片段的appbar上时，只有片段的appbar滚动