Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp

Index: third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp b/third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp
index df1c855549616284cc81191861fa9a16353e306a..02e2ad204a435d468a07235650e2c0cc8be424a9 100644
--- a/third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp
+++ b/third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp
@@ -38,6 +38,7 @@
 #include "core/loader/FrameLoadRequest.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/ThreadableLoadingContext.h"
+#include "core/loader/WorkerFetchContext.h"
 #include "core/probe/CoreProbes.h"
 #include "core/workers/ParentFrameTaskRunners.h"
 #include "core/workers/SharedWorkerGlobalScope.h"
@@ -50,6 +51,7 @@
 #include "core/workers/WorkerScriptLoader.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "platform/CrossThreadFunctional.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/heap/Handle.h"
 #include "platform/heap/Persistent.h"
 #include "platform/loader/fetch/ResourceResponse.h"
@@ -63,6 +65,7 @@
 #include "public/platform/WebString.h"
 #include "public/platform/WebURL.h"
 #include "public/platform/WebURLRequest.h"
+#include "public/platform/WebWorkerFetchContext.h"
 #include "public/platform/modules/serviceworker/WebServiceWorkerNetworkProvider.h"
 #include "public/web/WebDevToolsAgent.h"
 #include "public/web/WebFrame.h"
@@ -327,6 +330,20 @@ void WebSharedWorkerImpl::OnScriptLoaderFinished() {
           web_security_origin)));
   ProvideIndexedDBClientToWorker(worker_clients,
                                  IndexedDBClientImpl::Create(*worker_clients));
+
+  if (RuntimeEnabledFeatures::offMainThreadFetchEnabled()) {
+    std::unique_ptr<WebWorkerFetchContext> web_worker_fetch_context =
+        client_->CreateWorkerFetchContext(
+            WebLocalFrameImpl::FromFrame(main_frame_->GetFrame())
+                ->DataSource()
+                ->GetServiceWorkerNetworkProvider());
+    DCHECK(web_worker_fetch_context);
+    // TODO(horo): Set more information about the context (ex: DataSaverEnabled)
+    // to |web_worker_fetch_context|.
+    ProvideWorkerFetchContextToWorker(worker_clients,
+                                      std::move(web_worker_fetch_context));
+  }
+
   ContentSecurityPolicy* content_security_policy =
       main_script_loader_->ReleaseContentSecurityPolicy();
   WorkerThreadStartMode start_mode =