Move Task Scheduler Initialization From chrome/browser to Content

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 14cfceeae7f49613657cddb059c059f7a0cdcad3..908aa07ac321349ecf371302f485ae188f4851ac 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -31,6 +31,8 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/system_monitor/system_monitor.h"
+#include "base/task_scheduler/scheduler_worker_pool_params.h"
+#include "base/task_scheduler/task_scheduler.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -868,6 +870,17 @@ void BrowserMainLoop::CreateStartupTasks() {
 int BrowserMainLoop::CreateThreads() {
   TRACE_EVENT0("startup,rail", "BrowserMainLoop::CreateThreads");
 
+  std::vector<base::SchedulerWorkerPoolParams> params_vector;
+  base::TaskScheduler::WorkerPoolIndexForTraitsCallback
+      index_to_traits_callback;
+  GetContentClient()->browser()->GetTaskSchedulerInitializationParams(
+      &params_vector, &index_to_traits_callback);
+
+  base::TaskScheduler::CreateAndSetDefaultTaskScheduler(
+      params_vector, index_to_traits_callback);
+
+  GetContentClient()->browser()->PerformRedirectionToTaskScheduler();
+
   base::Thread::Options io_message_loop_options;
   io_message_loop_options.message_loop_type = base::MessageLoop::TYPE_IO;
   base::Thread::Options ui_message_loop_options;
@@ -1197,6 +1210,11 @@ void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
     URLDataManager::DeleteDataSources();
   }
 
+  {
+    TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:TaskScheduler");
+    base::TaskScheduler::GetInstance()->Shutdown();

[fdoray, 2016/12/06 21:14:12]

TaskScheduler is initialized just before browser threads. Any reason why it's
not shutdown immediately after browser threads?

[robliao, 2016/12/07 00:57:32]

Looks like I was too aggressive with the lifetime as some of the components
above assume a no-threads world. I've moved it up to right after the
BrowserThreadImpl::ShutdownThreadPool.

+  }
+
   if (parts_) {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
     parts_->PostDestroyThreads();