Remove @color/appbar_background

chrome/android/java/res/layout/selectable_list_layout.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2016 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
 <merge xmlns:android="http://schemas.android.com/apk/res/android">
     <ViewStub
         android:id="@+id/action_bar_stub"
         android:inflatedId="@+id/action_bar"
         android:layout_width="match_parent"
         android:layout_height="?attr/actionBarSize"
-        android:background="@color/appbar_background" />
+        android:background="@color/default_primary_color" />
 
     <FrameLayout
         android:id="@+id/list_content"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="?attr/actionBarSize" >
 
         <android.support.v7.widget.RecyclerView
             android:id="@+id/recycler_view"
             android:layout_width="match_parent"
@@ skipping 17 matching lines @@
             android:layout_gravity="center" />
     </FrameLayout>
 
     <org.chromium.chrome.browser.widget.FadingShadowView
         android:id="@+id/shadow"
         android:layout_width="match_parent"
         android:layout_height="@dimen/action_bar_shadow_height"
         android:layout_marginTop="?attr/actionBarSize" />
 
 </merge>