Remove ResourceFetcher's access to a real FetchContext at frame detach time

Source/core/fetch/ImageResourceTest.cpp

Index: Source/core/fetch/ImageResourceTest.cpp
diff --git a/Source/core/fetch/ImageResourceTest.cpp b/Source/core/fetch/ImageResourceTest.cpp
index 302401ebd6a0f7005595fffa86df46ecdcb56280..7a3690478b7ab4121a1ddd76e858afce90ae1f4f 100644
--- a/Source/core/fetch/ImageResourceTest.cpp
+++ b/Source/core/fetch/ImageResourceTest.cpp
@@ -131,7 +131,7 @@ TEST(ImageResourceTest, CancelOnDetach)
     KURL testURL(ParsedURLString, "http://www.test.com/cancelTest.html");
     URLTestHelpers::registerMockedURLLoad(testURL, "cancelTest.html", "text/html");
 
-    RefPtrWillBeRawPtr<ResourceFetcher> fetcher = ResourceFetcher::create(FetchContext::create());
+    RefPtrWillBeRawPtr<ResourceFetcher> fetcher = ResourceFetcher::create(nullptr);
 
     // Emulate starting a real load.
     ResourcePtr<ImageResource> cachedImage = new ImageResource(ResourceRequest(testURL));