packages/SystemUI/res/layout/system_bar_notification_panel.xml

<!--
  Copyright (C) 2006 The Android Open Source Project
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
 
       http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->

<!--    android:background="@drawable/system_bar_closed_default_background" -->
<com.android.systemui.statusbar.tablet.NotificationPanel
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:systemui="http://schemas.android.com/apk/res/com.android.systemui"
    android:id="@+id/panel_root"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:gravity="right"
    >

    <ImageView android:id="@+id/clear_all_button"
        android:layout_width="wrap_content"
        android:layout_height="@*android:dimen/system_bar_height"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:layout_marginRight="20dp"
        android:paddingLeft="15dp"
        android:paddingRight="15dp"
        android:src="@drawable/ic_notify_clear"
        android:visibility="invisible"
        android:contentDescription="@string/accessibility_clear_all"
        />

    <RelativeLayout
        android:id="@+id/content_parent"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="8dp"
        >

        <include layout="@layout/system_bar_notification_panel_title"
            android:layout_width="478dp"
            android:layout_height="224dp"
            android:layout_alignParentTop="true"
            android:layout_alignParentRight="true"
            />

        <LinearLayout
            android:id="@+id/content_frame"
            android:background="@drawable/notify_panel_notify_bg"
            android:layout_height="wrap_content"
            android:layout_width="478dp"
            android:orientation="vertical"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:layout_marginTop="178dp"
            >
            <ScrollView
                android:id="@+id/notification_scroller"
                android:layout_height="wrap_content"
                android:layout_width="match_parent"
                android:layout_weight="1"
                >
                <com.android.systemui.statusbar.policy.NotificationRowLayout
                    android:id="@+id/content"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:gravity="center_horizontal|bottom"
                    android:clickable="true"
                    android:focusable="true"
                    android:descendantFocusability="afterDescendants"
                    systemui:rowHeight="@dimen/notification_height"
                    />
            </ScrollView>
        </LinearLayout>
    </RelativeLayout>

</com.android.systemui.statusbar.tablet.NotificationPanel>