Partially implement WorkerFetchContext and WorkerThreadableLoadingContext and add virtual tests

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

Index: third_party/WebKit/Source/core/loader/ThreadableLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/ThreadableLoader.cpp b/third_party/WebKit/Source/core/loader/ThreadableLoader.cpp
index bf836d3d8de9c0974f9523e72bb32f0c5922450c..e7d0ad5027c5157b974f3364cb4a92d56927d4a2 100644
--- a/third_party/WebKit/Source/core/loader/ThreadableLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/ThreadableLoader.cpp
@@ -34,8 +34,10 @@
 #include "core/dom/ExecutionContext.h"
 #include "core/loader/DocumentThreadableLoader.h"
 #include "core/loader/ThreadableLoadingContext.h"
+#include "core/loader/WorkerFetchContext.h"
 #include "core/loader/WorkerThreadableLoader.h"
 #include "core/workers/WorkerGlobalScope.h"
+#include "platform/RuntimeEnabledFeatures.h"
 
 namespace blink {
 
@@ -47,6 +49,15 @@ ThreadableLoader* ThreadableLoader::Create(
   DCHECK(client);
 
   if (context.IsWorkerGlobalScope()) {
+    if (RuntimeEnabledFeatures::offMainThreadFetchEnabled()) {
+      WorkerFetchContext* worker_fetch_contrext =
+          ToWorkerGlobalScope(&context)->GetFetchContext();
+      if (worker_fetch_contrext) {

[kinuko, 2017/05/13 13:26:42]

When this could return nullptr?

[horo, 2017/05/13 17:05:45]

Ah, yes.
This should be DCHECK().

+        return DocumentThreadableLoader::Create(

[kinuko, 2017/05/13 13:26:42]

Can you add a TODO to DocumentThreadableLoader to note that it now works without
document and should be probably renamed?

[horo, 2017/05/13 17:05:45]

Done.

+            *ThreadableLoadingContext::Create(*ToWorkerGlobalScope(&context)),
+            client, options, resource_loader_options);
+      }
+    }
     return WorkerThreadableLoader::Create(ToWorkerGlobalScope(context), client,
                                           options, resource_loader_options);
   }