Partially implement WorkerFetchContext and WorkerThreadableLoadingContext and add virtual tests

third_party/WebKit/Source/platform/exported/WebURLRequest.cpp

Index: third_party/WebKit/Source/platform/exported/WebURLRequest.cpp
diff --git a/third_party/WebKit/Source/platform/exported/WebURLRequest.cpp b/third_party/WebKit/Source/platform/exported/WebURLRequest.cpp
index e214fdd5b023b1c31f2322ddaa450bda00f1678a..1d95bc7f7ca1be780ffa564f9a9f131fe06d263c 100644
--- a/third_party/WebKit/Source/platform/exported/WebURLRequest.cpp
+++ b/third_party/WebKit/Source/platform/exported/WebURLRequest.cpp
@@ -31,7 +31,6 @@
 #include "public/platform/WebURLRequest.h"
 
 #include <memory>
-#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/loader/fetch/ResourceRequest.h"
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/Noncopyable.h"
@@ -402,9 +401,7 @@ bool WebURLRequest::IsExternalRequest() const {
 }
 
 WebURLRequest::LoadingIPCType WebURLRequest::GetLoadingIPCType() const {
-  if (RuntimeEnabledFeatures::loadingWithMojoEnabled())
-    return WebURLRequest::LoadingIPCType::kMojo;
-  return WebURLRequest::LoadingIPCType::kChromeIPC;
+  return resource_request_->GetLoadingIPCType();
 }
 
 void WebURLRequest::SetNavigationStartTime(double navigation_start_seconds) {