Read the bare minimum of data from the WebAPK launch intent.

chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java

Index: chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
diff --git a/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java b/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
index a99304ef3b8417a86aed263f9a72749595574467..a2a62a32c9e9d47466f3c17ad5dccb561faf9d84 100644
--- a/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
+++ b/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
@@ -6,7 +6,7 @@ package org.chromium.webapk.shell_apk;
 
 import android.app.Activity;
 import android.content.ActivityNotFoundException;
-import android.content.Context;
+import android.content.ComponentName;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
@@ -18,7 +18,6 @@ import android.util.Log;
 import org.chromium.webapk.lib.common.WebApkConstants;
 import org.chromium.webapk.lib.common.WebApkMetaDataKeys;
 
-import java.lang.reflect.Method;
 import java.net.URISyntaxException;
 
 /**
@@ -64,13 +63,13 @@ public class MainActivity extends Activity {
      * Launches WebAPK.
      */
     private void launch() {
-        if (launchHostBrowserInWebApkMode()) {
-            return;
-        }
         String startUrl = getStartUrl();
         if (startUrl == null) {
             return;
         }
+        if (launchHostBrowserInWebApkMode(startUrl)) {
+            return;
+        }
         if (launchBrowser(startUrl)) {
             return;
         }
@@ -81,25 +80,25 @@ public class MainActivity extends Activity {
      * Launches host browser in WebAPK mode.
      * @return True if successful.
      */
-    private boolean launchHostBrowserInWebApkMode() {
-        ClassLoader webApkClassLoader = HostBrowserClassLoader.getClassLoaderInstance(
-                this, HOST_BROWSER_LAUNCHER_CLASS_NAME);
-        if (webApkClassLoader == null) {
-            Log.w(TAG, "Unable to create ClassLoader.");
-            return false;
-        }
+    private boolean launchHostBrowserInWebApkMode(String startUrl) {
+        Log.v(TAG, "Url of the WebAPK: " + startUrl);
+        String packageName = getPackageName();
+        Log.v(TAG, "Package name of the WebAPK:" + packageName);
+
+        String runtimeHost = WebApkUtils.getHostBrowserPackageName(this);
+        int source = getIntent().getIntExtra(WebApkConstants.EXTRA_SOURCE, 0);
+        Intent intent = new Intent();
+        intent.setComponent(new ComponentName(
+                runtimeHost, "org.chromium.chrome.browser.webapps.WebappLauncherActivity"));
+        intent.putExtra(WebApkConstants.EXTRA_ID, WebApkConstants.WEBAPK_ID_PREFIX + packageName)
+                .putExtra(WebApkConstants.EXTRA_URL, startUrl)
+                .putExtra(WebApkConstants.EXTRA_SOURCE, source)
+                .putExtra(WebApkConstants.EXTRA_WEBAPK_PACKAGE_NAME, packageName);
 
         try {
-            Class<?> hostBrowserLauncherClass =
-                    webApkClassLoader.loadClass(HOST_BROWSER_LAUNCHER_CLASS_NAME);
-            Method launchMethod = hostBrowserLauncherClass.getMethod(
-                    "launch", Context.class, Intent.class, Bundle.class);
-            Object hostBrowserLauncherInstance = hostBrowserLauncherClass.newInstance();
-            Bundle bundle = new Bundle();
-            bundle.putInt(KEY_APP_ICON_ID, R.mipmap.app_icon);
-            launchMethod.invoke(hostBrowserLauncherInstance, this, getIntent(), bundle);
+            startActivity(intent);
             return true;
-        } catch (Exception e) {
+        } catch (ActivityNotFoundException e) {
             Log.w(TAG, "Unable to launch browser in WebAPK mode.");
             e.printStackTrace();
             return false;