Initialize TaskScheduler in Mash.

chrome/app/mash/mash_runner.cc

Index: chrome/app/mash/mash_runner.cc
diff --git a/chrome/app/mash/mash_runner.cc b/chrome/app/mash/mash_runner.cc
index 940804f7e70b6e1db0e9078f6a678dbf9a06b768..3c6d88b7cb0cca546287ea69947df72081f886ae 100644
--- a/chrome/app/mash/mash_runner.cc
+++ b/chrome/app/mash/mash_runner.cc
@@ -15,6 +15,8 @@
 #include "base/message_loop/message_loop.h"
 #include "base/process/launch.h"
 #include "base/run_loop.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "base/trace_event/trace_event.h"
 #include "components/tracing/common/trace_to_console.h"
 #include "components/tracing/common/tracing_switches.h"
@@ -127,6 +129,10 @@ int MashRunner::Run() {
 }
 
 void MashRunner::RunMain() {
+  constexpr int kNumThreads = 3;

[sky, 2016/11/23 21:47:35]

Where does the 3 come from? Is there a constant else where we should be using?

[fdoray, 2016/11/23 21:53:43]

From the SequencedWorkerPool that TaskScheduler replaces
https://cs.chromium.org/chromium/src/services/service_manager/standalone/cont...


I didn't put TaskScheduler initialization in service_manager::Context because it
enables the post_task.h API for the whole process (would be weird to enable
post_task.h for the whole process when a Context is initialized for the whole
process - I prefer to put it here to make it clear that any code running in a
Mash process may use post_task.h).

+  base::TaskScheduler::CreateAndSetSimpleTaskScheduler(kNumThreads);
+  base::SequencedWorkerPool::EnableWithRedirectionToTaskSchedulerForProcess();
+
   // TODO(sky): refactor BackgroundServiceManager so can supply own context, we
   // shouldn't we using context as it has a lot of stuff we don't really want
   // in chrome.
@@ -169,9 +175,16 @@ void MashRunner::RunMain() {
   // Ping mash_session to ensure an instance is brought up
   context_->connector()->Connect("mash_session");
   base::RunLoop().Run();
+
+  base::TaskScheduler::GetInstance()->Shutdown();
 }
 
 int MashRunner::RunChild() {
+  // TODO(fdoray): Add TaskScheduler initialization code in
+  // service_manager::ServiceRunner. TaskScheduler can't be initialized here
+  // because it wouldn't be visible to the service's dynamic library.
+  // https://crbug.com/664996
+
   base::FilePath path =
       base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
           switches::kChildProcess);