webapps: add splashscreen for installed webapps

chrome/android/java/res/values-v17/styles.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2014 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. -->
 
 <resources xmlns:tools="http://schemas.android.com/tools">
     <!-- Q: Why put style resources under values-v17/ ?
          A: Problem:
             1. paddingStart causes a crash on Galaxy Tab&Note b/8351339.
             2. So we wrote a build script(generate_v14_compatible_resources.py) to convert
@@ skipping 26 matching lines @@
         <item name="android:windowExitTransition" tools:targetApi="21">@null</item>
         <item name="android:windowSharedElementEnterTransition" tools:targetApi="21">@transition/move_image</item>
         <item name="android:windowSharedElementExitTransition" tools:targetApi="21">@transition/move_image</item>
     </style>
 
     <style name="WebappTheme" parent="MainTheme">
         <item name="android:windowBackground">@null</item>
         <item name="android:windowDisablePreview">true</item>
     </style>
 
+    <style name="WebAppSplashScreenTextAppearanceTitle" parent="TextAppearance.AppCompat.Title">
+        <item name="android:fontFamily">sans-serif-condensed</item>
+        <item name="android:textSize">@dimen/webapp_splash_title_size</item>
+        <item name="android:textColor">@color/webapp_splash_title</item>
+    </style>
+
     <!-- A theme for alert dialogs. The colors are copied from MainTheme, and the window
          dimensions are copied from *.MinWidth theme variants. Sadly there is no
          AppCompat.Light.Dialog.Alert or even AppCompat.Light.Dialog.MinWidth. -->
     <style name="AlertDialogTheme" parent="Theme.AppCompat.Light.Dialog">
         <item name="android:textColorHighlight">@color/text_highlight_color</item>
         <item name="android:windowMinWidthMajor">@android:dimen/dialog_min_width_major</item>
         <item name="android:windowMinWidthMinor">@android:dimen/dialog_min_width_minor</item>
 
         <!--  Overriding AppCompat values -->
         <item name="colorAccent">@color/light_active_color</item>
@@ skipping 315 matching lines @@
     <style name="LocationBarButton">
         <item name="android:background">@null</item>
     </style>
     <style name="ToolbarButton">
         <item name="android:background">?attr/selectableItemBackground</item>
         <item name="android:layout_width">48dp</item>
         <item name="android:layout_height">56dp</item>
         <item name="android:scaleType">center</item>
     </style>
 </resources>