jni: Forbid inappropriate JNI parameter conversions.

components/cronet/android/cronet_library_loader.cc

 // Copyright 2014 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.
 
 #include "components/cronet/android/cronet_library_loader.h"
 
 #include <jni.h>
 
 #include "base/android/base_jni_onload.h"
 #include "base/android/base_jni_registrar.h"
@@ skipping 72 matching lines @@
 }
 
 void CronetOnUnLoad(JavaVM* jvm, void* reserved) {
   base::android::LibraryLoaderExitHook();
 }
 
 void CronetInitApplicationContext(JNIEnv* env,
                                   const JavaParamRef<jclass>& jcaller,
                                   const JavaParamRef<jobject>& japp_context) {
   // Set application context.
-  base::android::ScopedJavaLocalRef<jobject> scoped_app_context(env,
-                                                                japp_context);
-  base::android::InitApplicationContext(env, scoped_app_context);
+  base::android::InitApplicationContext(env, japp_context);
 }
 
 void CronetInitOnMainThread(JNIEnv* env, const JavaParamRef<jclass>& jcaller) {
 #if !defined(USE_ICU_ALTERNATIVES_ON_ANDROID)
   base::i18n::InitializeICU();
 #endif
 
   // TODO(bengr): Remove once Data Reduction Proxy no longer needs this for
   // configuration information.
   base::CommandLine::Init(0, nullptr);
   DCHECK(!base::MessageLoop::current());
   DCHECK(!g_main_message_loop);
   g_main_message_loop = new base::MessageLoopForUI();
   base::MessageLoopForUI::current()->Start();
   DCHECK(!g_network_change_notifier);
   net::NetworkChangeNotifier::SetFactory(
       new net::NetworkChangeNotifierFactoryAndroid());
   g_network_change_notifier = net::NetworkChangeNotifier::Create();
 }
 
 ScopedJavaLocalRef<jstring> GetCronetVersion(
     JNIEnv* env,
     const JavaParamRef<jclass>& jcaller) {
   return base::android::ConvertUTF8ToJavaString(env, CRONET_VERSION);
 }
 
 }  // namespace cronet