Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp

Index: third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp b/third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp
index 6acd6833d14aa1989cea9188bbb255a3c6f07ea9..27accf2113b4f6256fa2e7cffdeb23fa24b248bd 100644
--- a/third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp
+++ b/third_party/WebKit/Source/web/WebEmbeddedWorkerImpl.cpp
@@ -38,6 +38,7 @@
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoadRequest.h"
 #include "core/loader/ThreadableLoadingContext.h"
+#include "core/loader/WorkerFetchContext.h"
 #include "core/probe/CoreProbes.h"
 #include "core/workers/ParentFrameTaskRunners.h"
 #include "core/workers/WorkerClients.h"
@@ -433,6 +434,18 @@ void WebEmbeddedWorkerImpl::StartWorkerThread() {
       worker_clients,
       WTF::WrapUnique(worker_context_client_->CreateServiceWorkerProvider()));
 
+  std::unique_ptr<WebWorkerFetchContextInfo> web_worker_fetch_context_info =
+      WTF::WrapUnique(
+          worker_context_client_->CreateServiceWorkerFetchContextInfo());
+  // |web_worker_fetch_context_info| is null if off-main-thread-fetch is
+  // disabled.
+  if (web_worker_fetch_context_info) {
+    // TODO(horo): Set more information about the context (ex: DataSaverEnabled)
+    // to |web_worker_fetch_context_info|.
+    ProvideWorkerFetchContextInfoToWorker(
+        worker_clients, std::move(web_worker_fetch_context_info));
+  }
+
   // We need to set the CSP to both the shadow page's document and the
   // ServiceWorkerGlobalScope.
   document->InitContentSecurityPolicy(