[Reland] Refactor WebappRegistry into a singleton instance.

chrome/browser/android/chrome_jni_registrar.cc

Index: chrome/browser/android/chrome_jni_registrar.cc
diff --git a/chrome/browser/android/chrome_jni_registrar.cc b/chrome/browser/android/chrome_jni_registrar.cc
index 81d8e6a802ad9f0de438c57cd1c2e37b9747aabf..3fe7eb7f802c59034496b9e1966885c7bc98c911 100644
--- a/chrome/browser/android/chrome_jni_registrar.cc
+++ b/chrome/browser/android/chrome_jni_registrar.cc
@@ -104,7 +104,6 @@
 #include "chrome/browser/android/webapk/webapk_installer.h"
 #include "chrome/browser/android/webapk/webapk_update_manager.h"
 #include "chrome/browser/android/webapps/add_to_homescreen_manager.h"
-#include "chrome/browser/android/webapps/webapp_registry.h"
 #include "chrome/browser/autofill/android/personal_data_manager_android.h"
 #include "chrome/browser/dom_distiller/dom_distiller_service_factory_android.h"
 #include "chrome/browser/dom_distiller/tab_utils_android.h"
@@ -390,7 +389,6 @@ static base::android::RegistrationMethod kChromeRegisteredMethods[] = {
     {"WarmupManager", RegisterWarmupManager},
     {"WebApkInstaller", WebApkInstaller::Register},
     {"WebApkUpdateManager", WebApkUpdateManager::Register},
-    {"WebappRegistry", WebappRegistry::RegisterWebappRegistry},
     {"WebContentsFactory", RegisterWebContentsFactory},
     {"WebsitePreferenceBridge", RegisterWebsitePreferenceBridge},
     {"WebsiteSettingsPopupAndroid",