Skip foreign fetch when the skipServiceWorker flag is set on a request.

third_party/WebKit/Source/core/fetch/ResourceLoader.cpp

Index: third_party/WebKit/Source/core/fetch/ResourceLoader.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ResourceLoader.cpp b/third_party/WebKit/Source/core/fetch/ResourceLoader.cpp
index 2be163c8007ac3cbd6c698124b132e8482bdc250..47ba192ec7184346ec64f112983a14d75d35556c 100644
--- a/third_party/WebKit/Source/core/fetch/ResourceLoader.cpp
+++ b/third_party/WebKit/Source/core/fetch/ResourceLoader.cpp
@@ -152,7 +152,7 @@ bool ResourceLoader::responseNeedsAccessControlCheck() const
 
 void ResourceLoader::didReceiveResponse(WebURLLoader*, const WebURLResponse& response, WebDataConsumerHandle* rawHandle)
 {
-    ASSERT(!response.isNull());
+    DCHECK(!response.isNull());
     // |rawHandle|'s ownership is transferred to the callee.
     std::unique_ptr<WebDataConsumerHandle> handle = wrapUnique(rawHandle);
     const ResourceResponse& resourceResponse = response.toResourceResponse();
@@ -162,10 +162,10 @@ void ResourceLoader::didReceiveResponse(WebURLLoader*, const WebURLResponse& res
             if (response.wasFallbackRequiredByServiceWorker()) {
                 m_loader.reset();
                 m_loader = wrapUnique(Platform::current()->createURLLoader());
-                ASSERT(m_loader);
+                DCHECK(m_loader);
                 ResourceRequest request = m_resource->lastResourceRequest();
-                ASSERT(!request.skipServiceWorker());
-                request.setSkipServiceWorker(true);
+                DCHECK_EQ(request.skipServiceWorker(), WebURLRequest::SkipServiceWorker::None);
+                request.setSkipServiceWorker(WebURLRequest::SkipServiceWorker::Controlling);

[horo, 2016/06/28 12:10:02]

This code is executed when a CORS request was send to the SW but respondWith()
is not called.
In this case, we should skip all SW.

[Marijn Kruisselbrink, 2016/06/28 17:06:12]

Also see my reply in DocumentThreadableLoader, but no, in this case we should
not skip foreign fetch service workers since CORS requests generally are exactly
the requests we do want foreign fetch to intercept. The layout test I added that
injects a cross origin script tag in a service worker controlled page exercises
this code, and I do expect that script tag to be intercepted by foreign fetch.

                 m_loader->loadAsynchronously(WrappedResourceRequest(request), this);
                 return;
             }