We have a problem in the process on destroying WebContentsImpl because

android_webview/native/aw_settings.cc

 // Copyright (c) 2013 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 "android_webview/native/aw_settings.h"
 
 #include "android_webview/browser/renderer_host/aw_render_view_host_ext.h"
 #include "android_webview/common/aw_content_client.h"
 #include "android_webview/native/aw_contents.h"
 #include "base/android/jni_android.h"
@@ skipping 249 matching lines @@
   // settings via RVHExt only ever updates the 'current' RVH.
   // In android_webview we don't swap out the RVH on cross-site navigations, so
   // we shouldn't have to deal with the multiple RVH per WebContents case. That
   // in turn means that the newly created RVH is always the 'current' RVH
   // (since we only ever go from 0 to 1 RVH instances) and hence the DCHECK.
   DCHECK(web_contents()->GetRenderViewHost() == render_view_host);
 
   UpdateEverything();
 }
 
-void AwSettings::WebContentsDestroyed(content::WebContents* web_contents) {
+void AwSettings::WebContentsDestroyed() {
   delete this;
 }
 
 void AwSettings::PopulateWebPreferences(WebPreferences* web_prefs) {
   JNIEnv* env = base::android::AttachCurrentThread();
   CHECK(env);
   ScopedJavaLocalRef<jobject> scoped_obj = aw_settings_.get(env);
   jobject obj = scoped_obj.obj();
   if (!obj) return;
   // Grab the lock and call PopulateWebPreferencesLocked.
@@ skipping 158 matching lines @@
 
 static jstring GetDefaultUserAgent(JNIEnv* env, jclass clazz) {
   return base::android::ConvertUTF8ToJavaString(env, GetUserAgent()).Release();
 }
 
 bool RegisterAwSettings(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android_webview