Flip this back to true. IdleHandlers should certainly be being scheduled when

content/public/renderer/content_renderer_client.cc

 // 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.
 
 #include "content/public/renderer/content_renderer_client.h"
 
 namespace content {
 
 SkBitmap* ContentRendererClient::GetSadPluginBitmap() {
   return NULL;
@@ skipping 67 matching lines @@
 blink::WebThemeEngine* ContentRendererClient::OverrideThemeEngine() {
   return NULL;
 }
 
 blink::WebSpeechSynthesizer* ContentRendererClient::OverrideSpeechSynthesizer(
     blink::WebSpeechSynthesizerClient* client) {
   return NULL;
 }
 
 bool ContentRendererClient::RunIdleHandlerWhenWidgetsHidden() {
-  // TODO(wfh): http://crbug.com/381820 change this back to true after testing
-  // whether this affects tabs hanging.
-  return false;
+  return true;
 }
 
 bool ContentRendererClient::AllowPopup() {
   return false;
 }
 
 #ifdef OS_ANDROID
 bool ContentRendererClient::HandleNavigation(
     RenderFrame* render_frame,
     DocumentState* document_state,
@@ skipping 85 matching lines @@
 bool ContentRendererClient::IsPluginAllowedToUseVideoDecodeAPI(
     const GURL& url) {
   return false;
 }
 
 bool ContentRendererClient::IsPluginAllowedToUseDevChannelAPIs() {
   return false;
 }
 
 }  // namespace content