[scheduler] Remove blink::scheduler::TaskQueue from public API.

third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc

Index: third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc b/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc
index a93dca0474ba97202e2b12c32a923b9577e2c5fa..f53f535188943277aa0b885032fa89a35002c8b5 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.cc
@@ -8,9 +8,9 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
+#include "platform/scheduler/base/task_queue.h"
 #include "platform/scheduler/base/time_converter.h"
 #include "platform/scheduler/child/scheduler_tqm_delegate.h"
-#include "public/platform/scheduler/base/task_queue.h"
 
 namespace blink {
 namespace scheduler {
@@ -72,9 +72,15 @@ void WorkerSchedulerImpl::Init() {
   idle_helper_.EnableLongIdlePeriod();
 }
 
-scoped_refptr<TaskQueue> WorkerSchedulerImpl::DefaultTaskRunner() {
+scoped_refptr<base::SingleThreadTaskRunner>
+WorkerSchedulerImpl::DefaultTaskRunner() {
   DCHECK(initialized_);
-  return helper_.DefaultTaskRunner();
+  return helper_.DefaultTaskQueue();
+}
+
+scoped_refptr<TaskQueue> WorkerSchedulerImpl::DefaultTaskQueue() {
+  DCHECK(initialized_);
+  return helper_.DefaultTaskQueue();
 }
 
 scoped_refptr<SingleThreadIdleTaskRunner>