Cache the current WebPreferences on RenderViewHostImpl (try #2).

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 140 matching lines @@
 }
 
 void AwSettings::UpdateWebkitPreferencesLocked(JNIEnv* env, jobject obj) {
   if (!web_contents()) return;
   AwRenderViewHostExt* render_view_host_ext = GetAwRenderViewHostExt();
   if (!render_view_host_ext) return;
 
   content::RenderViewHost* render_view_host =
       web_contents()->GetRenderViewHost();
   if (!render_view_host) return;
-  render_view_host->UpdateWebkitPreferences(
-      render_view_host->GetWebkitPreferences());
+  render_view_host->OnWebkitPreferencesChanged();
 }
 
 void AwSettings::UpdateInitialPageScaleLocked(JNIEnv* env, jobject obj) {
   AwRenderViewHostExt* rvhe = GetAwRenderViewHostExt();
   if (!rvhe) return;
 
   float initial_page_scale_percent =
       Java_AwSettings_getInitialPageScalePercentLocked(env, obj);
   if (initial_page_scale_percent == 0) {
     rvhe->SetInitialPageScale(-1);
@@ skipping 233 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