android: Upstream app zygote implementation

Enable zygote in chromium code in chrome and content shell.

Requires crrev.com/i/2340835 for private code to build.

Change-Id: I99a3f550a81b0c877389ccb839b59afba8a7d447
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1976015
Commit-Queue: Bo <boliu@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726444}

chrome/android/java/AndroidManifest.xml

@@ -131,9 +131,7 @@ by a child template that "extends" this file.
         android:largeHeap="false"
         android:manageSpaceActivity="@string/manage_space_activity"
         android:supportsRtl="true"
-        {% if (use_zygote|default(false) == 'true') %}
         android:zygotePreloadName="org.chromium.content.app.ZygotePreload"
-        {% endif %}
         {% if backup_key is defined %}
         android:allowBackup="true"
         android:backupAgent="org.chromium.chrome.browser.ChromeBackupAgent"
@@ -1193,7 +1191,7 @@ by a child template that "extends" this file.
             android:permission="{{ manifest_package }}.permission.CHILD_SERVICE"
             android:isolatedProcess="true"
             android:exported="{{sandboxed_service_exported|default(false)}}"
-            {% if (use_zygote|default(false) == 'true') and (i == 0) %}
+            {% if (i == 0) %}
             android:useAppZygote="true"
             {% endif %}
             {% if (sandboxed_service_exported|default(false)) == 'true' %}

chrome/android/java/monochrome_public_bundle__base_bundle_module.AndroidManifest.expected

@@ -90,7 +90,8 @@
       android:networkSecurityConfig="@xml/network_security_config"
       android:roundIcon="@drawable/ic_launcher_round"
       android:supportsRtl="true"
-      android:use32bitAbi="true">
+      android:use32bitAbi="true"
+      android:zygotePreloadName="org.chromium.content.app.ZygotePreload">
     <activity
         android:autoRemoveFromRecents="false"
         android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize|uiMode|density"
@@ -1672,6 +1673,7 @@
         android:name="org.chromium.content.app.SandboxedProcessService0"
         android:permission="org.chromium.chrome.permission.CHILD_SERVICE"
         android:process=":sandboxed_process0"
+        android:useAppZygote="true"
         android:visibleToInstantApps="true"
         tools:ignore="ExportedService"/>
     <service

content/public/android/BUILD.gn

@@ -118,6 +118,7 @@ android_library("content_java") {
     "java/src/org/chromium/content/app/PrivilegedProcessService3.java",
     "java/src/org/chromium/content/app/PrivilegedProcessService4.java",
     "java/src/org/chromium/content/app/SandboxedProcessService.java",
+    "java/src/org/chromium/content/app/ZygotePreload.java",
     "java/src/org/chromium/content/browser/AppWebMessagePort.java",
     "java/src/org/chromium/content/browser/AudioFocusDelegate.java",
     "java/src/org/chromium/content/browser/BackgroundSyncNetworkObserver.java",

content/public/android/java/src/org/chromium/content/app/ZygotePreload.java

+// Copyright 2019 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.
+
+package org.chromium.content.app;
+
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
+import android.content.pm.ApplicationInfo;
+import android.os.Build;
+
+import org.chromium.base.JNIUtils;
+import org.chromium.base.Log;
+import org.chromium.base.library_loader.LibraryLoader;
+
+/**
+ * Class used in android:zygotePreloadName attribute of manifest.
+ * Code in this class runs in the zygote. It runs in a limited environment
+ * (eg no application) and cannot communicate with any other app process,
+ * so care must be taken when writing code in this class. Eg it should not
+ * create any thread.
+ */
+@TargetApi(Build.VERSION_CODES.Q)
+public class ZygotePreload implements android.app.ZygotePreload {
+    private static final String TAG = "ZygotePreload";
+
+    @SuppressLint("Override")
+    @Override
+    public void doPreload(ApplicationInfo appInfo) {
+        try {
+            JNIUtils.enableSelectiveJniRegistration();
+            LibraryLoader.getInstance().loadNowInZygote(appInfo);
+        } catch (Throwable e) {
+            // Ignore any exception. Child service can continue loading.
+            Log.w(TAG, "Exception in zygote", e);
+        }
+    }
+}

content/shell/android/shell_apk/AndroidManifest.xml.jinja2

@@ -24,6 +24,7 @@
 
     <application android:name="org.chromium.content_shell_apk.ContentShellApplication"
             android:icon="@mipmap/app_icon"
+            android:zygotePreloadName="org.chromium.content.app.ZygotePreload"
             android:label="{% block application_label %}Content Shell{% endblock %}">
         <activity android:name="org.chromium.content_shell_apk.ContentShellActivity"
                   android:launchMode="singleTask"
@@ -54,6 +55,9 @@
         {% for i in range(num_sandboxed_services) %}
         <service android:name="org.chromium.content.app.SandboxedProcessService{{ i }}"
                  android:process=":sandboxed_process{{ i }}"
+                 {% if (i == 0) %}
+                 android:useAppZygote="true"
+                 {% endif %}
                  android:isolatedProcess="true"
                  android:exported="false" />
         {% endfor %}