[Chromecast] Turn CastContentWindow into an abstract interface.

chromecast/browser/android/apk/AndroidManifest.xml.jinja2

 <?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.
  -->
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="org.chromium.chromecast.shell">
 
     <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="22" />
 
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
 
     <application android:name="org.chromium.chromecast.shell.CastApplication"
                  android:icon="@mipmap/app_icon"
                  android:label="@string/app_name">
-        <activity android:name="org.chromium.chromecast.shell.CastShellActivity"
+        <activity android:name="org.chromium.chromecast.shell.CastWebContentsActivity"
                   android:theme="@style/CastShellTheme"
                   android:exported="true"
                   android:hardwareAccelerated="true"
-                  android:taskAffinity=".CastShellActivity"
+                  android:launchMode="standard"
+                  android:taskAffinity=".CastWebContentsActivity"
                   android:configChanges="orientation|keyboardHidden|keyboard|screenSize"
                   android:excludeFromRecents="true"
                   android:noHistory="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
         </activity>
 
         <!-- The following service entries exist in order to allow us to
@@ skipping 13 matching lines @@
                    android:value="{{ num_privileged_services }}"/>
         {% for i in range(num_privileged_services) %}
         <service android:name="org.chromium.content.app.PrivilegedProcessService{{ i }}"
                  android:process=":privileged_process{{ i }}"
                  android:isolatedProcess="false"
                  android:exported="false" />
         {% endfor %}
     </application>
 
 </manifest>