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 Chrome's ClassLoader to create a
+ * {@link ChildProcessServiceImpl} object which loads Chrome's native libraries, initializes JNI
+ * and creates the renderer.
+ */
+public class WebApkSandboxedProcessService extends Service {
+    private static final String CHILD_PROCESS_SERVICE_IMPL_CLASS_NAME =
+            "org.chromium.content.app.ChildProcessServiceImpl";
+    private static final String TAG = "cr_WebApkSandboxedProcessService";
+
+    private Class<?> mChildProcessServiceImplClass;
+    private Object mChildProcessServiceImplInstance;
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+
+        try {

[michaelbai, 2016/06/20 17:58:46]

Why don't you create ChildProcessServiceImpl directly?

[Xi Han, 2016/06/20 18:18:45]

We want to keep WebAPK is small, so it doesn't depend on any Chrome's code.
Since ChildProcessServiceImpl is in Chrome' code base, even though WebAPK (gn
target is shell_apk) uses Chrome's ClassLoader, the shell_apk doesn't have
knowledge of the ChildProcessServiceImpl, so it has to use reflection to call
any function in ChildProcessServiceImpl.

+            Context hostBrowserContext =
+                    WebApkUtils.getHostBrowserContext(getApplicationContext());
+            ClassLoader classLoader = hostBrowserContext.getClassLoader();
+            mChildProcessServiceImplClass =
+                    classLoader.loadClass(CHILD_PROCESS_SERVICE_IMPL_CLASS_NAME);
+            mChildProcessServiceImplInstance = mChildProcessServiceImplClass.newInstance();
+
+            Method createMethod = mChildProcessServiceImplClass.getMethod("create",
+                    Context.class, Context.class);
+            createMethod.invoke(mChildProcessServiceImplInstance, getApplicationContext(),
+                    hostBrowserContext);
+        } catch (Exception e) {
+            Log.d(TAG, "Unable to create a ChildProcessServiceImpl for the WebAPK.", e);
+        }
+    }
+
+    @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);
+        }
+        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);
+        }
+    }
+}