Remove most native WebContents references from Java

android_webview/native/aw_contents.h

 // Copyright (c) 2012 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.
 
 #ifndef ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_
 #define ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_
 
 #include <jni.h>
 #include <list>
 #include <string>
@@ skipping 71 matching lines @@
                                  const std::string& realm);
 
   // Methods called from Java.
   void SetJavaPeers(JNIEnv* env,
                     jobject obj,
                     jobject aw_contents,
                     jobject web_contents_delegate,
                     jobject contents_client_bridge,
                     jobject io_thread_client,
                     jobject intercept_navigation_delegate);
-  jlong GetWebContents(JNIEnv* env, jobject obj);
+  base::android::ScopedJavaLocalRef<jobject> GetWebContents(JNIEnv* env,
+                                                            jobject obj);
 
   void Destroy(JNIEnv* env, jobject obj);
   void DocumentHasImages(JNIEnv* env, jobject obj, jobject message);
   void GenerateMHTML(JNIEnv* env, jobject obj, jstring jpath, jobject callback);
   void CreatePdfExporter(JNIEnv* env, jobject obj, jobject pdfExporter);
   void AddVisitedLinks(JNIEnv* env, jobject obj, jobjectArray jvisited_links);
   base::android::ScopedJavaLocalRef<jbyteArray> GetCertificate(
       JNIEnv* env, jobject obj);
   void RequestNewHitTestDataAt(JNIEnv* env,
                                jobject obj,
@@ skipping 155 matching lines @@
   GLViewRendererManager::Key renderer_manager_key_;
 
   DISALLOW_COPY_AND_ASSIGN(AwContents);
 };
 
 bool RegisterAwContents(JNIEnv* env);
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_