[scheduler] Remove WebThreadImplForUtilityThread from public API.

content/utility/utility_blink_platform_impl.cc

Index: content/utility/utility_blink_platform_impl.cc
diff --git a/content/utility/utility_blink_platform_impl.cc b/content/utility/utility_blink_platform_impl.cc
index c184297b5ac2a08cf70d5af2b960d3dc7271b933..31e14731308df51eea4304375d9d3d1d72992d01 100644
--- a/content/utility/utility_blink_platform_impl.cc
+++ b/content/utility/utility_blink_platform_impl.cc
@@ -4,12 +4,13 @@
 
 #include "content/utility/utility_blink_platform_impl.h"
 
-#include "third_party/WebKit/public/platform/scheduler/utility/webthread_impl_for_utility_thread.h"
+#include "third_party/WebKit/public/platform/scheduler/child/webthread_base.h"
 
 namespace content {
 
 UtilityBlinkPlatformImpl::UtilityBlinkPlatformImpl()
-    : main_thread_(new blink::scheduler::WebThreadImplForUtilityThread()) {}
+    : main_thread_(blink::scheduler::WebThreadBase::InitializeUtilityThread()) {
+}
 
 UtilityBlinkPlatformImpl::~UtilityBlinkPlatformImpl() {
 }