Use TaskScheduler instead of blocking pool in plugin_service_impl.cc.

content/browser/plugin_service_impl.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/browser/plugin_service_impl.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/waitable_event.h"
-#include "base/threading/sequenced_worker_pool.h"
+#include "base/task_scheduler/post_task.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "content/browser/ppapi_plugin_process_host.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/pepper_plugin_list.h"
 #include "content/common/plugin_list.h"
 #include "content/common/view_messages.h"
@@ skipping 59 matching lines @@
     counted = true;
     UMA_HISTOGRAM_ENUMERATION("Plugin.FlashUsage", TOTAL_BROWSER_PROCESSES,
                               FLASH_USAGE_ENUM_COUNT);
   }
 }
 
 PluginServiceImpl::~PluginServiceImpl() {
 }
 
 void PluginServiceImpl::Init() {
-  plugin_list_task_runner_ =
-      BrowserThread::GetBlockingPool()
-          ->GetSequencedTaskRunnerWithShutdownBehavior(
-              base::SequencedWorkerPool::GetSequenceToken(),
-              base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
+  plugin_list_task_runner_ = base::CreateSequencedTaskRunnerWithTraits(
+      base::TaskTraits()
+          .MayBlock()
+          .WithPriority(base::TaskPriority::BACKGROUND)

[boliu, 2017/04/24 18:41:25]

probably should be user visible, I assume this is a request to populate the
plugins page, in which case that's a user waiting for the request

[fdoray, 2017/04/26 19:35:07]

Done.

+          .WithShutdownBehavior(base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN));
   PluginList::Singleton()->set_will_load_plugins_callback(
       base::Bind(&WillLoadPluginsCallback, &plugin_list_sequence_checker_));
 
   RegisterPepperPlugins();
 }
 
 PpapiPluginProcessHost* PluginServiceImpl::FindPpapiPluginProcess(
     const base::FilePath& plugin_path,
     const base::FilePath& profile_data_directory) {
   for (PpapiPluginProcessHostIterator iter; !iter.Done(); ++iter) {
@@ skipping 300 matching lines @@
 }
 
 bool PluginServiceImpl::PpapiDevChannelSupported(
     BrowserContext* browser_context,
     const GURL& document_url) {
   return GetContentClient()->browser()->IsPluginAllowedToUseDevChannelAPIs(
       browser_context, document_url);
 }
 
 }  // namespace content