Fix RNTester integration with Flipper (#27482)

Summary:
There was a reflective call to a non-existent class. It did, however,
exist in the template, so I copied it over from there and updated
the references accordingly.
Pull Request resolved: https://github.com/facebook/react-native/pull/27482

Test Plan:
Built it and ran it. Works again with the latest Flipper desktop app.

![Screenshot 2019-12-11 16 02 40](https://user-images.githubusercontent.com/9906/70637975-02405580-1c30-11ea-9fec-23860c59cdb6.png)

Reviewed By: rickhanlonii

Differential Revision: D18933530

Pulled By: passy

fbshipit-source-id: 4515d7baaad9a9fff9a4b66e1cbf8a75889e6e45

RNTester/android/app/src/debug/java/com/facebook/react/uiapp/ReactNativeFlipper.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.uiapp;
+
+import android.content.Context;
+import com.facebook.flipper.android.AndroidFlipperClient;
+import com.facebook.flipper.android.utils.FlipperUtils;
+import com.facebook.flipper.core.FlipperClient;
+import com.facebook.flipper.plugins.crashreporter.CrashReporterPlugin;
+import com.facebook.flipper.plugins.databases.DatabasesFlipperPlugin;
+import com.facebook.flipper.plugins.fresco.FrescoFlipperPlugin;
+import com.facebook.flipper.plugins.inspector.DescriptorMapping;
+import com.facebook.flipper.plugins.inspector.InspectorFlipperPlugin;
+import com.facebook.flipper.plugins.network.FlipperOkhttpInterceptor;
+import com.facebook.flipper.plugins.network.NetworkFlipperPlugin;
+import com.facebook.flipper.plugins.react.ReactFlipperPlugin;
+import com.facebook.flipper.plugins.sharedpreferences.SharedPreferencesFlipperPlugin;
+import com.facebook.react.ReactInstanceManager;
+import com.facebook.react.bridge.ReactContext;
+import com.facebook.react.modules.network.NetworkingModule;
+import okhttp3.OkHttpClient;
+
+public class ReactNativeFlipper {
+  public static void initializeFlipper(Context context, ReactInstanceManager reactInstanceManager) {
+    if (FlipperUtils.shouldEnableFlipper(context)) {
+      final FlipperClient client = AndroidFlipperClient.getInstance(context);
+
+      client.addPlugin(new InspectorFlipperPlugin(context, DescriptorMapping.withDefaults()));
+      client.addPlugin(new ReactFlipperPlugin());
+      client.addPlugin(new DatabasesFlipperPlugin(context));
+      client.addPlugin(new SharedPreferencesFlipperPlugin(context));
+      client.addPlugin(CrashReporterPlugin.getInstance());
+
+      NetworkFlipperPlugin networkFlipperPlugin = new NetworkFlipperPlugin();
+      NetworkingModule.setCustomClientBuilder(
+          new NetworkingModule.CustomClientBuilder() {
+            @Override
+            public void apply(OkHttpClient.Builder builder) {
+              builder.addNetworkInterceptor(new FlipperOkhttpInterceptor(networkFlipperPlugin));
+            }
+          });
+      client.addPlugin(networkFlipperPlugin);
+      client.start();
+
+      // Fresco Plugin needs to ensure that ImagePipelineFactory is initialized
+      // Hence we run if after all native modules have been initialized
+      ReactContext reactContext = reactInstanceManager.getCurrentReactContext();
+      if (reactContext == null) {
+        reactInstanceManager.addReactInstanceEventListener(
+            new ReactInstanceManager.ReactInstanceEventListener() {
+              @Override
+              public void onReactContextInitialized(ReactContext reactContext) {
+                reactInstanceManager.removeReactInstanceEventListener(this);
+                reactContext.runOnNativeModulesQueueThread(
+                    new Runnable() {
+                      @Override
+                      public void run() {
+                        client.addPlugin(new FrescoFlipperPlugin());
+                      }
+                    });
+              }
+            });
+      } else {
+        client.addPlugin(new FrescoFlipperPlugin());
+      }
+    }
+  }
+}

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -11,11 +11,11 @@ import android.app.Application;
 import android.content.Context;
 import com.facebook.react.BuildConfig;
 import com.facebook.react.ReactApplication;
+import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.react.views.text.ReactFontManager;
-import com.facebook.soloader.SoLoader;
 import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
 import java.util.List;
@@ -48,7 +48,7 @@ public class RNTesterApplication extends Application implements ReactApplication
   public void onCreate() {
     ReactFontManager.getInstance().addCustomFont(this, "Rubik", R.font.rubik);
     super.onCreate();
-    initializeFlipper(this);
+    initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
   }
 
   @Override
@@ -56,15 +56,25 @@ public class RNTesterApplication extends Application implements ReactApplication
     return mReactNativeHost;
   }
 
-  private static void initializeFlipper(Context context) {
+  /**
+   * Loads Flipper in React Native templates. Call this in the onCreate method with something like
+   * initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
+   *
+   * @param context
+   * @param reactInstanceManager
+   */
+  private static void initializeFlipper(
+      Context context, ReactInstanceManager reactInstanceManager) {
     if (BuildConfig.DEBUG) {
       try {
         /*
          We use reflection here to pick up the class that initializes Flipper,
         since Flipper library is not available in release mode
         */
-        Class<?> aClass = Class.forName("com.facebook.flipper.ReactNativeFlipper");
-        aClass.getMethod("initializeFlipper", Context.class).invoke(null, context);
+        Class<?> aClass = Class.forName("com.facebook.react.uiapp.ReactNativeFlipper");
+        aClass
+            .getMethod("initializeFlipper", Context.class, ReactInstanceManager.class)
+            .invoke(null, context, reactInstanceManager);
       } catch (ClassNotFoundException e) {
         e.printStackTrace();
       } catch (NoSuchMethodException e) {

template/android/app/src/main/java/com/helloworld/MainApplication.java

@@ -51,6 +51,7 @@ public class MainApplication extends Application implements ReactApplication {
    * initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
    *
    * @param context
+   * @param reactInstanceManager
    */
   private static void initializeFlipper(
       Context context, ReactInstanceManager reactInstanceManager) {