Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/Source/core/loader/FrameFetchContext.cpp

Index: third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
index aad2404223ad5a4d6ec402328f81e4ac9c6f6034..bffba1a91cd25a8e4543d053687b0f6271568376 100644
--- a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
@@ -79,6 +79,7 @@
 #include "platform/network/NetworkUtils.h"
 #include "platform/weborigin/SchemeRegistry.h"
 #include "platform/wtf/Vector.h"
+#include "public/platform/Platform.h"
 #include "public/platform/WebCachePolicy.h"
 #include "public/platform/WebInsecureRequestPolicy.h"
 #include "public/platform/WebViewScheduler.h"
@@ -1030,6 +1031,10 @@ RefPtr<WebTaskRunner> FrameFetchContext::LoadingTaskRunner() const {
   return GetFrame()->FrameScheduler()->LoadingTaskRunner();
 }
 
+WebURLLoader* FrameFetchContext::CreateURLLoader() {
+  return Platform::Current()->CreateURLLoader();
+}
+
 DEFINE_TRACE(FrameFetchContext) {
   visitor->Trace(document_loader_);
   BaseFetchContext::Trace(visitor);