Android: fix appearance of settings window

Regressed in f0fc9ffb. activity_bar_activity_bg.xml can be
removed completely as it only existed for a pre-K workaround.

Bug: 1119675
Change-Id: I9c22de1e769c743600afe4fa1a8de8cd9913ea19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2366573
Auto-Submit: Evan Stade <estade@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800195}

chrome/android/chrome_java_resources.gni

@@ -646,7 +646,6 @@ chrome_java_resources = [
   "java/res/drawable-xxxhdpi/verify_checkmark.png",
   "java/res/drawable/accessibility_tab_switcher_divider.xml",
   "java/res/drawable/account_picker_background.xml",
-  "java/res/drawable/action_bar_activity_bg.xml",
   "java/res/drawable/address.xml",
   "java/res/drawable/bg_white_dialog.xml",
   "java/res/drawable/bookmark_title_bar_shadow.xml",

chrome/android/java/res/drawable/action_bar_activity_bg.xml

-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2015 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. -->
-
-<!-- On pre-KitKat devices the window background extends above the action bar
-     and is normally hidden behind the status bar, but during window
-     transitions, is visible and looks glitchy. As a workaround, we make the top
-     50dp of the window background transparent. 50dp is greater than the status
-     bar height (to prevent the visual glitch) and less than the status bar +
-     action bar height (to ensure the background covers the entire activity). On
-     KitKat and later devices, Android clips the window background correctly and
-     these shenanigans aren't needed. http://crbug.com/448012 -->
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
-    <item
-        android:drawable="@color/default_bg_color"
-        android:top="50dp" />
-</layer-list>

chrome/android/java/res/values/styles.xml

@@ -42,9 +42,6 @@
         <!-- With ActionBar -->
         <item name="windowActionBar">true</item>
         <item name="windowNoTitle">false</item>
-
-        <!-- Window properties -->
-        <item name="android:windowBackground">@drawable/action_bar_activity_bg</item>
     </style>
 
     <style name="Base.Theme.Chromium.WithWindowAnimation">