Introduce background Download process to android

chrome/android/java/AndroidManifest.xml

Index: chrome/android/java/AndroidManifest.xml
diff --git a/chrome/android/java/AndroidManifest.xml b/chrome/android/java/AndroidManifest.xml
index b21f383843ea300c1ff7495f9142b1e2034eedb8..da4c6224a4f3d38d0deebdd3378130b51c3af0f3 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -642,6 +642,13 @@ android:value="true" />
             android:exported="false" />
         {% endfor %}
 
+        <!-- Background download process, it may outlive chrome if download does not finish
+             when user kills chrome -->
+        <service android:name="org.chromium.content.app.DownloadProcessService"
+            android:process=":download"
+            android:permission="{{ manifest_package }}.permission.CHILD_SERVICE"
+            android:exported="false"/>
+
         <receiver android:name="org.chromium.chrome.browser.download.DownloadBroadcastReceiver"
             android:exported="false">
             <intent-filter>