Expose SingleThreadTaskRunnerThreadMode in post_task.h

base/task_scheduler/task_scheduler_impl_unittest.cc

Index: base/task_scheduler/task_scheduler_impl_unittest.cc
diff --git a/base/task_scheduler/task_scheduler_impl_unittest.cc b/base/task_scheduler/task_scheduler_impl_unittest.cc
index 3098bf3a9044d3d5b874e0eac4187ae6f95d5364..69bd9f977d9944252d47bd27977113d93695c452 100644
--- a/base/task_scheduler/task_scheduler_impl_unittest.cc
+++ b/base/task_scheduler/task_scheduler_impl_unittest.cc
@@ -121,8 +121,10 @@ scoped_refptr<TaskRunner> CreateTaskRunnerWithTraitsAndExecutionMode(
       return scheduler->CreateTaskRunnerWithTraits(traits);
     case test::ExecutionMode::SEQUENCED:
       return scheduler->CreateSequencedTaskRunnerWithTraits(traits);
-    case test::ExecutionMode::SINGLE_THREADED:
-      return scheduler->CreateSingleThreadTaskRunnerWithTraits(traits);
+    case test::ExecutionMode::SINGLE_THREADED: {

[gab, 2017/05/15 21:02:26]

In CL which will introduce real sharding we should also have a test param that
makes this go through both SingleThreadTaskRunnerThreadMode.

[robliao, 2017/05/15 21:19:10]

Agreed.

+      return scheduler->CreateSingleThreadTaskRunnerWithTraits(
+          traits, SingleThreadTaskRunnerThreadMode::SHARED);
+    }
   }
   ADD_FAILURE() << "Unknown ExecutionMode";
   return nullptr;