Upstream: Renderers are running in WebAPKs.

chrome/android/webapk/libs/common/src/org/chromium/webapk/lib/common/WebApkSandboxedProcessService.java

+// Copyright 2016 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.webapk.lib.common;
+
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.IBinder;
+import android.util.Log;
+
+import java.lang.reflect.Method;
+
+/**
+ * Child process service hosted by WebAPKs. This class uses BaseDexClassLoader to load Chrome's
+ * {@link ChildProcessServiceImpl} which loads Chrome's native libraries, initializes JNI and
+ * creates renderer processes.

[pkotwicz, 2016/06/15 14:13:50]

Nit: Can you please update the comment? This class no longer uses
BaseDexClassLoader

[Xi Han, 2016/06/15 17:10:39]

Done.

+ */
+public class WebApkSandboxedProcessService extends Service {
+    private static final String CHILD_PROCESS_SERVICE_IMPL =

[pkotwicz, 2016/06/15 14:13:50]

Nit: Rename to CHILD_PROCESS_SERVICE_IMPL_CLASS_NAME

[Xi Han, 2016/06/15 17:10:39]

Done.

+            "org.chromium.content.app.ChildProcessServiceImpl";
+    private static final String TAG = "cr_WebApkSandboxedProcessService";
+
+    private Class<?> mChildProcessServiceImplClass;
+    private Object mChildProcessServiceImplInstance;
+    private static ClassLoader sClassLoader;
+
+    /**
+     * Gets/creates ClassLoader for loading {@link CHILD_PROCESS_SERVICE_IMPL}.
+     * @param context WebAPK's context.
+     * @return The ClassLoader.
+     */
+    private static ClassLoader getClassLoaderInstance(Context context) {
+        if (sClassLoader == null) {
+            sClassLoader = createClassLoader(context);
+        }
+        return sClassLoader;
+    }
+
+    /**
+     * Creates ClassLoader for loading {@link CHILD_PROCESS_SERVICE_IMPL}.
+     * @param context WebAPK's context.
+     * @return The ClassLoader.
+     */
+    private static ClassLoader createClassLoader(Context context) {
+        Context remoteContext = WebApkUtils.getHostBrowserContext(context);
+        return remoteContext.getClassLoader();
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+
+        try {

[pkotwicz, 2016/06/15 14:13:50]

Can you just do:
Context hostBrowserContext =
WebApkUtils.getHostBrowserContext(getApplicationContext());
ClassLoader classLoader = hostBrowserContext.getClassLoader();

and remove the getClassLoaderInstance() function. I think that
Context#getClassLoader() is fast. Can you double check? You are already calling
WebApkUtils#getHostBrowserContext() on line 65

[Xi Han, 2016/06/15 17:10:39]

You are right, removed since we have to call the
WebApkUtils#getHostBrowserContext() anyway.

[pkotwicz, 2016/06/15 17:51:00]

Thank you for making this change!

+            ClassLoader classLoader = getClassLoaderInstance(
+                    getApplicationContext());
+            mChildProcessServiceImplClass =
+                    classLoader.loadClass(CHILD_PROCESS_SERVICE_IMPL);
+            mChildProcessServiceImplInstance = mChildProcessServiceImplClass.newInstance();
+
+            Method createMethod = mChildProcessServiceImplClass.getMethod("create",
+                    Context.class, Context.class);
+            createMethod.invoke(mChildProcessServiceImplInstance, getApplicationContext(),
+                    WebApkUtils.getHostBrowserContext(getApplicationContext()));
+        } catch (Exception e) {
+            Log.d(TAG, "Unable to create a ChildProcessServiceImpl for the WebAPK.");
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        // We call stopSelf() to request that this service be stopped as soon as the client
+        // unbinds. Otherwise the system may keep it around and available for a reconnect. The
+        // child processes do not currently support reconnect; they must be initialized from
+        // scratch every time.
+        stopSelf();
+        try {
+            Method bindMethod = mChildProcessServiceImplClass.getMethod(
+                    "bind", Intent.class);
+            return (IBinder) bindMethod.invoke(mChildProcessServiceImplInstance, intent);
+        } catch (Exception e) {
+            Log.d(TAG, "Unable to bind to the WebApkSandboxedProcessService.");
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        try {
+            Method destroyMethod = mChildProcessServiceImplClass.getMethod("destroy");
+            destroyMethod.invoke(mChildProcessServiceImplInstance);
+        } catch (Exception e) {
+            Log.d(TAG, "Unable to destroy the WebApkSandboxedProcessService.");
+            e.printStackTrace();
+        }
+    }
+}