Implement the infrastructure of creating WorkerFetchContext in worker global scope.

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 1a8a8f6aaf80370d08c0a96a4e0970be6185eeca..d33e4647d072b2f92e75a1bc9835f2408e21f0a1 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -8,6 +8,7 @@
 #include <utility>
 
 #include "base/command_line.h"
+#include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/guid.h"
 #include "base/lazy_instance.h"
@@ -40,6 +41,8 @@
 #include "content/common/file_utilities_messages.h"
 #include "content/common/frame_messages.h"
 #include "content/common/render_process_messages.h"
+#include "content/common/worker_url_loader_factory_provider.mojom.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/service_manager_connection.h"
 #include "content/public/common/webplugininfo.h"
@@ -66,6 +69,7 @@
 #include "content/renderer/mojo/blink_interface_provider_impl.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/renderer_clipboard_delegate.h"
+#include "content/renderer/service_worker/worker_fetch_context_impl.h"
 #include "content/renderer/webclipboard_impl.h"
 #include "content/renderer/webgraphicscontext3d_provider_impl.h"
 #include "content/renderer/webpublicsuffixlist_impl.h"
@@ -442,6 +446,17 @@ void RendererBlinkPlatformImpl::CacheMetadataInCacheStorage(
           cacheStorageOrigin, cacheStorageCacheName.Utf8()));
 }
 
+std::unique_ptr<blink::WebWorkerFetchContext>
+RendererBlinkPlatformImpl::CreateWorkerFetchContext() {
+  if (!base::FeatureList::IsEnabled(features::kOffMainThreadFetch))
+    return nullptr;
+  mojom::WorkerURLLoaderFactoryProviderPtr worker_url_loader_factory_provider;
+  GetInterfaceProvider()->GetInterface(
+      mojo::MakeRequest(&worker_url_loader_factory_provider));
+  return base::MakeUnique<WorkerFetchContextImpl>(
+      worker_url_loader_factory_provider.PassInterface());
+}
+
 WebString RendererBlinkPlatformImpl::DefaultLocale() {
   return WebString::FromASCII(RenderThread::Get()->GetLocale());
 }