Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp

Index: third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp
index 15c1f33920f1d6ea47ae5009b9877e0679c52c79..a514234434bceb882b1155caea58c7bee62d768d 100644
--- a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp
+++ b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp
@@ -40,6 +40,7 @@
 #include "core/inspector/ConsoleMessage.h"
 #include "core/inspector/ConsoleMessageStorage.h"
 #include "core/inspector/WorkerThreadDebugger.h"
+#include "core/loader/WorkerFetchContext.h"
 #include "core/loader/WorkerThreadableLoader.h"
 #include "core/probe/CoreProbes.h"
 #include "core/workers/WorkerClients.h"
@@ -300,6 +301,13 @@ ExecutionContext* WorkerGlobalScope::GetExecutionContext() const {
   return const_cast<WorkerGlobalScope*>(this);
 }
 
+WorkerFetchContext* WorkerGlobalScope::FetchContext() {

[nhiroki, 2017/04/18 07:56:41]

DCHECK(base::FeatureList::IsEnabled(kOffMainThreadFetch))?

[horo, 2017/04/18 12:53:34]

Done.

+  if (fetch_context_)
+    return fetch_context_;
+  fetch_context_ = WorkerFetchContext::Create(*this);
+  return fetch_context_;
+}
+
 WorkerGlobalScope::WorkerGlobalScope(
     const KURL& url,
     const String& user_agent,
@@ -376,6 +384,7 @@ DEFINE_TRACE(WorkerGlobalScope) {
   visitor->Trace(timers_);
   visitor->Trace(event_listeners_);
   visitor->Trace(pending_error_events_);
+  visitor->Trace(fetch_context_);
   ExecutionContext::Trace(visitor);
   EventTargetWithInlineData::Trace(visitor);
   SecurityContext::Trace(visitor);